sqlite3.h
1 /* 2 ** 2001-09-15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef SQLITE3_H 34 #define SQLITE3_H 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Facilitate override of interface linkage and calling conventions. 47 ** Be aware that these macros may not be used within this particular 48 ** translation of the amalgamation and its associated header file. 49 ** 50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the 51 ** compiler that the target identifier should have external linkage. 52 ** 53 ** The SQLITE_CDECL macro is used to set the calling convention for 54 ** public functions that accept a variable number of arguments. 55 ** 56 ** The SQLITE_APICALL macro is used to set the calling convention for 57 ** public functions that accept a fixed number of arguments. 58 ** 59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated. 60 ** 61 ** The SQLITE_CALLBACK macro is used to set the calling convention for 62 ** function pointers. 63 ** 64 ** The SQLITE_SYSAPI macro is used to set the calling convention for 65 ** functions provided by the operating system. 66 ** 67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and 68 ** SQLITE_SYSAPI macros are used only when building for environments 69 ** that require non-default calling conventions. 70 */ 71 #ifndef SQLITE_EXTERN 72 # define SQLITE_EXTERN extern 73 #endif 74 #ifndef SQLITE_API 75 # define SQLITE_API 76 #endif 77 #ifndef SQLITE_CDECL 78 # define SQLITE_CDECL 79 #endif 80 #ifndef SQLITE_APICALL 81 # define SQLITE_APICALL 82 #endif 83 #ifndef SQLITE_STDCALL 84 # define SQLITE_STDCALL SQLITE_APICALL 85 #endif 86 #ifndef SQLITE_CALLBACK 87 # define SQLITE_CALLBACK 88 #endif 89 #ifndef SQLITE_SYSAPI 90 # define SQLITE_SYSAPI 91 #endif 92 93 /* 94 ** These no-op macros are used in front of interfaces to mark those 95 ** interfaces as either deprecated or experimental. New applications 96 ** should not use deprecated interfaces - they are supported for backwards 97 ** compatibility only. Application writers should be aware that 98 ** experimental interfaces are subject to change in point releases. 99 ** 100 ** These macros used to resolve to various kinds of compiler magic that 101 ** would generate warning messages when they were used. But that 102 ** compiler magic ended up generating such a flurry of bug reports 103 ** that we have taken it all out and gone back to using simple 104 ** noop macros. 105 */ 106 #define SQLITE_DEPRECATED 107 #define SQLITE_EXPERIMENTAL 108 109 /* 110 ** Ensure these symbols were not defined by some previous header file. 111 */ 112 #ifdef SQLITE_VERSION 113 # undef SQLITE_VERSION 114 #endif 115 #ifdef SQLITE_VERSION_NUMBER 116 # undef SQLITE_VERSION_NUMBER 117 #endif 118 119 /* 120 ** CAPI3REF: Compile-Time Library Version Numbers 121 ** 122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 123 ** evaluates to a string literal that is the SQLite version in the 124 ** format "X.Y.Z" where X is the major version number (always 3 for 125 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 128 ** numbers used in [SQLITE_VERSION].)^ 129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 130 ** be larger than the release from which it is derived. Either Y will 131 ** be held constant and Z will be incremented or else Y will be incremented 132 ** and Z will be reset to zero. 133 ** 134 ** Since [version 3.6.18] ([dateof:3.6.18]), 135 ** SQLite source code has been stored in the 136 ** <a href="http://fossil-scm.org/">Fossil configuration management 137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 138 ** a string which identifies a particular check-in of SQLite 139 ** within its configuration management system. ^The SQLITE_SOURCE_ID 140 ** string contains the date and time of the check-in (UTC) and a SHA1 141 ** or SHA3-256 hash of the entire source tree. If the source code has 142 ** been edited in any way since it was last checked in, then the last 143 ** four hexadecimal digits of the hash may be modified. 144 ** 145 ** See also: [sqlite3_libversion()], 146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 147 ** [sqlite_version()] and [sqlite_source_id()]. 148 */ 149 #define SQLITE_VERSION "3.51.1" 150 #define SQLITE_VERSION_NUMBER 3051001 151 #define SQLITE_SOURCE_ID "2025-11-28 17:28:25 281fc0e9afc38674b9b0991943b9e9d1e64c6cbdb133d35f6f5c87ff6af38a88" 152 #define SQLITE_SCM_BRANCH "branch-3.51" 153 #define SQLITE_SCM_TAGS "release version-3.51.1" 154 #define SQLITE_SCM_DATETIME "2025-11-28T17:28:25.933Z" 155 156 /* 157 ** CAPI3REF: Run-Time Library Version Numbers 158 ** KEYWORDS: sqlite3_version sqlite3_sourceid 159 ** 160 ** These interfaces provide the same information as the [SQLITE_VERSION], 161 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 162 ** but are associated with the library instead of the header file. ^(Cautious 163 ** programmers might include assert() statements in their application to 164 ** verify that values returned by these interfaces match the macros in 165 ** the header, and thus ensure that the application is 166 ** compiled with matching library and header files. 167 ** 168 ** <blockquote><pre> 169 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 170 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 171 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 172 ** </pre></blockquote>)^ 173 ** 174 ** ^The sqlite3_version[] string constant contains the text of the 175 ** [SQLITE_VERSION] macro. ^The sqlite3_libversion() function returns a 176 ** pointer to the sqlite3_version[] string constant. The sqlite3_libversion() 177 ** function is provided for use in DLLs since DLL users usually do not have 178 ** direct access to string constants within the DLL. ^The 179 ** sqlite3_libversion_number() function returns an integer equal to 180 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 181 ** a pointer to a string constant whose value is the same as the 182 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 183 ** using an edited copy of [the amalgamation], then the last four characters 184 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 185 ** 186 ** See also: [sqlite_version()] and [sqlite_source_id()]. 187 */ 188 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 189 SQLITE_API const char *sqlite3_libversion(void); 190 SQLITE_API const char *sqlite3_sourceid(void); 191 SQLITE_API int sqlite3_libversion_number(void); 192 193 /* 194 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 195 ** 196 ** ^The sqlite3_compileoption_used() function returns 0 or 1 197 ** indicating whether the specified option was defined at 198 ** compile time. ^The SQLITE_ prefix may be omitted from the 199 ** option name passed to sqlite3_compileoption_used(). 200 ** 201 ** ^The sqlite3_compileoption_get() function allows iterating 202 ** over the list of options that were defined at compile time by 203 ** returning the N-th compile time option string. ^If N is out of range, 204 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 205 ** prefix is omitted from any strings returned by 206 ** sqlite3_compileoption_get(). 207 ** 208 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 209 ** and sqlite3_compileoption_get() may be omitted by specifying the 210 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 211 ** 212 ** See also: SQL functions [sqlite_compileoption_used()] and 213 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 214 */ 215 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 216 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 217 SQLITE_API const char *sqlite3_compileoption_get(int N); 218 #else 219 # define sqlite3_compileoption_used(X) 0 220 # define sqlite3_compileoption_get(X) ((void*)0) 221 #endif 222 223 /* 224 ** CAPI3REF: Test To See If The Library Is Threadsafe 225 ** 226 ** ^The sqlite3_threadsafe() function returns zero if and only if 227 ** SQLite was compiled with mutexing code omitted due to the 228 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 229 ** 230 ** SQLite can be compiled with or without mutexes. When 231 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 232 ** are enabled and SQLite is threadsafe. When the 233 ** [SQLITE_THREADSAFE] macro is 0, 234 ** the mutexes are omitted. Without the mutexes, it is not safe 235 ** to use SQLite concurrently from more than one thread. 236 ** 237 ** Enabling mutexes incurs a measurable performance penalty. 238 ** So if speed is of utmost importance, it makes sense to disable 239 ** the mutexes. But for maximum safety, mutexes should be enabled. 240 ** ^The default behavior is for mutexes to be enabled. 241 ** 242 ** This interface can be used by an application to make sure that the 243 ** version of SQLite that it is linking against was compiled with 244 ** the desired setting of the [SQLITE_THREADSAFE] macro. 245 ** 246 ** This interface only reports on the compile-time mutex setting 247 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 248 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 249 ** can be fully or partially disabled using a call to [sqlite3_config()] 250 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 251 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 252 ** sqlite3_threadsafe() function shows only the compile-time setting of 253 ** thread safety, not any run-time changes to that setting made by 254 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 255 ** is unchanged by calls to sqlite3_config().)^ 256 ** 257 ** See the [threading mode] documentation for additional information. 258 */ 259 SQLITE_API int sqlite3_threadsafe(void); 260 261 /* 262 ** CAPI3REF: Database Connection Handle 263 ** KEYWORDS: {database connection} {database connections} 264 ** 265 ** Each open SQLite database is represented by a pointer to an instance of 266 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 267 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 268 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 269 ** and [sqlite3_close_v2()] are its destructors. There are many other 270 ** interfaces (such as 271 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 272 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 273 ** sqlite3 object. 274 */ 275 typedef struct sqlite3 sqlite3; 276 277 /* 278 ** CAPI3REF: 64-Bit Integer Types 279 ** KEYWORDS: sqlite_int64 sqlite_uint64 280 ** 281 ** Because there is no cross-platform way to specify 64-bit integer types 282 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 283 ** 284 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 285 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 286 ** compatibility only. 287 ** 288 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 289 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 290 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 291 ** between 0 and +18446744073709551615 inclusive. 292 */ 293 #ifdef SQLITE_INT64_TYPE 294 typedef SQLITE_INT64_TYPE sqlite_int64; 295 # ifdef SQLITE_UINT64_TYPE 296 typedef SQLITE_UINT64_TYPE sqlite_uint64; 297 # else 298 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 299 # endif 300 #elif defined(_MSC_VER) || defined(__BORLANDC__) 301 typedef __int64 sqlite_int64; 302 typedef unsigned __int64 sqlite_uint64; 303 #else 304 typedef long long int sqlite_int64; 305 typedef unsigned long long int sqlite_uint64; 306 #endif 307 typedef sqlite_int64 sqlite3_int64; 308 typedef sqlite_uint64 sqlite3_uint64; 309 310 /* 311 ** If compiling for a processor that lacks floating point support, 312 ** substitute integer for floating-point. 313 */ 314 #ifdef SQLITE_OMIT_FLOATING_POINT 315 # define double sqlite3_int64 316 #endif 317 318 /* 319 ** CAPI3REF: Closing A Database Connection 320 ** DESTRUCTOR: sqlite3 321 ** 322 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 323 ** for the [sqlite3] object. 324 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 325 ** the [sqlite3] object is successfully destroyed and all associated 326 ** resources are deallocated. 327 ** 328 ** Ideally, applications should [sqlite3_finalize | finalize] all 329 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 330 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 331 ** with the [sqlite3] object prior to attempting to close the object. 332 ** ^If the database connection is associated with unfinalized prepared 333 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 334 ** sqlite3_close() will leave the database connection open and return 335 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 336 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 337 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 338 ** connection immediately, it marks the database connection as an unusable 339 ** "zombie" and makes arrangements to automatically deallocate the database 340 ** connection after all prepared statements are finalized, all BLOB handles 341 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 342 ** is intended for use with host languages that are garbage collected, and 343 ** where the order in which destructors are called is arbitrary. 344 ** 345 ** ^If an [sqlite3] object is destroyed while a transaction is open, 346 ** the transaction is automatically rolled back. 347 ** 348 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 349 ** must be either a NULL 350 ** pointer or an [sqlite3] object pointer obtained 351 ** from [sqlite3_open()], [sqlite3_open16()], or 352 ** [sqlite3_open_v2()], and not previously closed. 353 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 354 ** argument is a harmless no-op. 355 */ 356 SQLITE_API int sqlite3_close(sqlite3*); 357 SQLITE_API int sqlite3_close_v2(sqlite3*); 358 359 /* 360 ** The type for a callback function. 361 ** This is legacy and deprecated. It is included for historical 362 ** compatibility and is not documented. 363 */ 364 typedef int (*sqlite3_callback)(void*,int,char**, char**); 365 366 /* 367 ** CAPI3REF: One-Step Query Execution Interface 368 ** METHOD: sqlite3 369 ** 370 ** The sqlite3_exec() interface is a convenience wrapper around 371 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 372 ** that allows an application to run multiple statements of SQL 373 ** without having to use a lot of C code. 374 ** 375 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 376 ** semicolon-separated SQL statements passed into its 2nd argument, 377 ** in the context of the [database connection] passed in as its 1st 378 ** argument. ^If the callback function of the 3rd argument to 379 ** sqlite3_exec() is not NULL, then it is invoked for each result row 380 ** coming out of the evaluated SQL statements. ^The 4th argument to 381 ** sqlite3_exec() is relayed through to the 1st argument of each 382 ** callback invocation. ^If the callback pointer to sqlite3_exec() 383 ** is NULL, then no callback is ever invoked and result rows are 384 ** ignored. 385 ** 386 ** ^If an error occurs while evaluating the SQL statements passed into 387 ** sqlite3_exec(), then execution of the current statement stops and 388 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 389 ** is not NULL then any error message is written into memory obtained 390 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 391 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 392 ** on error message strings returned through the 5th parameter of 393 ** sqlite3_exec() after the error message string is no longer needed. 394 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 395 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 396 ** NULL before returning. 397 ** 398 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 399 ** routine returns SQLITE_ABORT without invoking the callback again and 400 ** without running any subsequent SQL statements. 401 ** 402 ** ^The 2nd argument to the sqlite3_exec() callback function is the 403 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 404 ** callback is an array of pointers to strings obtained as if from 405 ** [sqlite3_column_text()], one for each column. ^If an element of a 406 ** result row is NULL then the corresponding string pointer for the 407 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 408 ** sqlite3_exec() callback is an array of pointers to strings where each 409 ** entry represents the name of a corresponding result column as obtained 410 ** from [sqlite3_column_name()]. 411 ** 412 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 413 ** to an empty string, or a pointer that contains only whitespace and/or 414 ** SQL comments, then no SQL statements are evaluated and the database 415 ** is not changed. 416 ** 417 ** Restrictions: 418 ** 419 ** <ul> 420 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 421 ** is a valid and open [database connection]. 422 ** <li> The application must not close the [database connection] specified by 423 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 424 ** <li> The application must not modify the SQL statement text passed into 425 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 426 ** <li> The application must not dereference the arrays or string pointers 427 ** passed as the 3rd and 4th callback parameters after it returns. 428 ** </ul> 429 */ 430 SQLITE_API int sqlite3_exec( 431 sqlite3*, /* An open database */ 432 const char *sql, /* SQL to be evaluated */ 433 int (*callback)(void*,int,char**,char**), /* Callback function */ 434 void *, /* 1st argument to callback */ 435 char **errmsg /* Error msg written here */ 436 ); 437 438 /* 439 ** CAPI3REF: Result Codes 440 ** KEYWORDS: {result code definitions} 441 ** 442 ** Many SQLite functions return an integer result code from the set shown 443 ** here in order to indicate success or failure. 444 ** 445 ** New error codes may be added in future versions of SQLite. 446 ** 447 ** See also: [extended result code definitions] 448 */ 449 #define SQLITE_OK 0 /* Successful result */ 450 /* beginning-of-error-codes */ 451 #define SQLITE_ERROR 1 /* Generic error */ 452 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 453 #define SQLITE_PERM 3 /* Access permission denied */ 454 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 455 #define SQLITE_BUSY 5 /* The database file is locked */ 456 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 457 #define SQLITE_NOMEM 7 /* A malloc() failed */ 458 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 459 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 460 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 461 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 462 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 463 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 464 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 465 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 466 #define SQLITE_EMPTY 16 /* Internal use only */ 467 #define SQLITE_SCHEMA 17 /* The database schema changed */ 468 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 469 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 470 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 471 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 472 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 473 #define SQLITE_AUTH 23 /* Authorization denied */ 474 #define SQLITE_FORMAT 24 /* Not used */ 475 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 476 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 477 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 478 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 479 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 480 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 481 /* end-of-error-codes */ 482 483 /* 484 ** CAPI3REF: Extended Result Codes 485 ** KEYWORDS: {extended result code definitions} 486 ** 487 ** In its default configuration, SQLite API routines return one of 30 integer 488 ** [result codes]. However, experience has shown that many of 489 ** these result codes are too coarse-grained. They do not provide as 490 ** much information about problems as programmers might like. In an effort to 491 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 492 ** and later) include 493 ** support for additional result codes that provide more detailed information 494 ** about errors. These [extended result codes] are enabled or disabled 495 ** on a per database connection basis using the 496 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 497 ** the most recent error can be obtained using 498 ** [sqlite3_extended_errcode()]. 499 */ 500 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 501 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 502 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 503 #define SQLITE_ERROR_RESERVESIZE (SQLITE_ERROR | (4<<8)) 504 #define SQLITE_ERROR_KEY (SQLITE_ERROR | (5<<8)) 505 #define SQLITE_ERROR_UNABLE (SQLITE_ERROR | (6<<8)) 506 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 507 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 508 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 509 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 510 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 511 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 512 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 513 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 514 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 515 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 516 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 517 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 518 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 519 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 520 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 521 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 522 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 523 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 524 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 525 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 526 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 527 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 528 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 529 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 530 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 531 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 532 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 533 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 534 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 535 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 536 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 537 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 538 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 539 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8)) 540 #define SQLITE_IOERR_BADKEY (SQLITE_IOERR | (35<<8)) 541 #define SQLITE_IOERR_CODEC (SQLITE_IOERR | (36<<8)) 542 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 543 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 544 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 545 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 546 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 547 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 548 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 549 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 550 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 551 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 552 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 553 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 554 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 555 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 556 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 557 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 558 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 559 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 560 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 561 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 562 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 563 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 564 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 565 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 566 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 567 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 568 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 569 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 570 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 571 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 572 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 573 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 574 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 575 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 576 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 577 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8)) 578 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 579 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 580 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 581 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 582 583 /* 584 ** CAPI3REF: Flags For File Open Operations 585 ** 586 ** These bit values are intended for use in the 587 ** 3rd parameter to the [sqlite3_open_v2()] interface and 588 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 589 ** 590 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 591 ** used as the third argument to the [sqlite3_open_v2()] interface. 592 ** The other flags have historically been ignored by sqlite3_open_v2(), 593 ** though future versions of SQLite might change so that an error is 594 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 595 ** Applications should not depend on the historical behavior. 596 ** 597 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 598 ** [sqlite3_open_v2()] does *not* cause the underlying database file 599 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 600 ** [sqlite3_open_v2()] has historically been a no-op and might become an 601 ** error in future versions of SQLite. 602 */ 603 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 604 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 605 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 606 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 607 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 608 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 609 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 610 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 611 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 612 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 613 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 614 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 615 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 616 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 617 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 618 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 619 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 620 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 621 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 622 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 623 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 624 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 625 626 /* Reserved: 0x00F00000 */ 627 /* Legacy compatibility: */ 628 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 629 630 631 /* 632 ** CAPI3REF: Device Characteristics 633 ** 634 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 635 ** object returns an integer which is a vector of these 636 ** bit values expressing I/O characteristics of the mass storage 637 ** device that holds the file that the [sqlite3_io_methods] 638 ** refers to. 639 ** 640 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 641 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 642 ** mean that writes of blocks that are nnn bytes in size and 643 ** are aligned to an address which is an integer multiple of 644 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 645 ** that when data is appended to a file, the data is appended 646 ** first then the size of the file is extended, never the other 647 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 648 ** information is written to disk in the same order as calls 649 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 650 ** after reboot following a crash or power loss, the only bytes in a 651 ** file that were written at the application level might have changed 652 ** and that adjacent bytes, even bytes within the same sector are 653 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 654 ** flag indicates that a file cannot be deleted when open. The 655 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 656 ** read-only media and cannot be changed even by processes with 657 ** elevated privileges. 658 ** 659 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 660 ** filesystem supports doing multiple write operations atomically when those 661 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 662 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 663 ** 664 ** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read 665 ** from the database file in amounts that are not a multiple of the 666 ** page size and that do not begin at a page boundary. Without this 667 ** property, SQLite is careful to only do full-page reads and write 668 ** on aligned pages, with the one exception that it will do a sub-page 669 ** read of the first page to access the database header. 670 */ 671 #define SQLITE_IOCAP_ATOMIC 0x00000001 672 #define SQLITE_IOCAP_ATOMIC512 0x00000002 673 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 674 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 675 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 676 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 677 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 678 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 679 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 680 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 681 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 682 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 683 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 684 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 685 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 686 #define SQLITE_IOCAP_SUBPAGE_READ 0x00008000 687 688 /* 689 ** CAPI3REF: File Locking Levels 690 ** 691 ** SQLite uses one of these integer values as the second 692 ** argument to calls it makes to the xLock() and xUnlock() methods 693 ** of an [sqlite3_io_methods] object. These values are ordered from 694 ** least restrictive to most restrictive. 695 ** 696 ** The argument to xLock() is always SHARED or higher. The argument to 697 ** xUnlock is either SHARED or NONE. 698 */ 699 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 700 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 701 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 702 #define SQLITE_LOCK_PENDING 3 /* xLock() only */ 703 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 704 705 /* 706 ** CAPI3REF: Synchronization Type Flags 707 ** 708 ** When SQLite invokes the xSync() method of an 709 ** [sqlite3_io_methods] object it uses a combination of 710 ** these integer values as the second argument. 711 ** 712 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 713 ** sync operation only needs to flush data to mass storage. Inode 714 ** information need not be flushed. If the lower four bits of the flag 715 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 716 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 717 ** to use Mac OS X style fullsync instead of fsync(). 718 ** 719 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 720 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 721 ** settings. The [synchronous pragma] determines when calls to the 722 ** xSync VFS method occur and applies uniformly across all platforms. 723 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 724 ** energetic or rigorous or forceful the sync operations are and 725 ** only make a difference on Mac OSX for the default SQLite code. 726 ** (Third-party VFS implementations might also make the distinction 727 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 728 ** operating systems natively supported by SQLite, only Mac OSX 729 ** cares about the difference.) 730 */ 731 #define SQLITE_SYNC_NORMAL 0x00002 732 #define SQLITE_SYNC_FULL 0x00003 733 #define SQLITE_SYNC_DATAONLY 0x00010 734 735 /* 736 ** CAPI3REF: OS Interface Open File Handle 737 ** 738 ** An [sqlite3_file] object represents an open file in the 739 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 740 ** implementations will 741 ** want to subclass this object by appending additional fields 742 ** for their own use. The pMethods entry is a pointer to an 743 ** [sqlite3_io_methods] object that defines methods for performing 744 ** I/O operations on the open file. 745 */ 746 typedef struct sqlite3_file sqlite3_file; 747 struct sqlite3_file { 748 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 749 }; 750 751 /* 752 ** CAPI3REF: OS Interface File Virtual Methods Object 753 ** 754 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 755 ** [sqlite3_file] object (or, more commonly, a subclass of the 756 ** [sqlite3_file] object) with a pointer to an instance of this object. 757 ** This object defines the methods used to perform various operations 758 ** against the open file represented by the [sqlite3_file] object. 759 ** 760 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 761 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 762 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 763 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 764 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 765 ** to NULL. 766 ** 767 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 768 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 769 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 770 ** flag may be ORed in to indicate that only the data of the file 771 ** and not its inode needs to be synced. 772 ** 773 ** The integer values to xLock() and xUnlock() are one of 774 ** <ul> 775 ** <li> [SQLITE_LOCK_NONE], 776 ** <li> [SQLITE_LOCK_SHARED], 777 ** <li> [SQLITE_LOCK_RESERVED], 778 ** <li> [SQLITE_LOCK_PENDING], or 779 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 780 ** </ul> 781 ** xLock() upgrades the database file lock. In other words, xLock() moves the 782 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to 783 ** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 784 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the 785 ** requested lock, then the call to xLock() is a no-op. 786 ** xUnlock() downgrades the database file lock to either SHARED or NONE. 787 ** If the lock is already at or below the requested lock state, then the call 788 ** to xUnlock() is a no-op. 789 ** The xCheckReservedLock() method checks whether any database connection, 790 ** either in this process or in some other process, is holding a RESERVED, 791 ** PENDING, or EXCLUSIVE lock on the file. It returns, via its output 792 ** pointer parameter, true if such a lock exists and false otherwise. 793 ** 794 ** The xFileControl() method is a generic interface that allows custom 795 ** VFS implementations to directly control an open file using the 796 ** [sqlite3_file_control()] interface. The second "op" argument is an 797 ** integer opcode. The third argument is a generic pointer intended to 798 ** point to a structure that may contain arguments or space in which to 799 ** write return values. Potential uses for xFileControl() might be 800 ** functions to enable blocking locks with timeouts, to change the 801 ** locking strategy (for example to use dot-file locks), to inquire 802 ** about the status of a lock, or to break stale locks. The SQLite 803 ** core reserves all opcodes less than 100 for its own use. 804 ** A [file control opcodes | list of opcodes] less than 100 is available. 805 ** Applications that define a custom xFileControl method should use opcodes 806 ** greater than 100 to avoid conflicts. VFS implementations should 807 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 808 ** recognize. 809 ** 810 ** The xSectorSize() method returns the sector size of the 811 ** device that underlies the file. The sector size is the 812 ** minimum write that can be performed without disturbing 813 ** other bytes in the file. The xDeviceCharacteristics() 814 ** method returns a bit vector describing behaviors of the 815 ** underlying device: 816 ** 817 ** <ul> 818 ** <li> [SQLITE_IOCAP_ATOMIC] 819 ** <li> [SQLITE_IOCAP_ATOMIC512] 820 ** <li> [SQLITE_IOCAP_ATOMIC1K] 821 ** <li> [SQLITE_IOCAP_ATOMIC2K] 822 ** <li> [SQLITE_IOCAP_ATOMIC4K] 823 ** <li> [SQLITE_IOCAP_ATOMIC8K] 824 ** <li> [SQLITE_IOCAP_ATOMIC16K] 825 ** <li> [SQLITE_IOCAP_ATOMIC32K] 826 ** <li> [SQLITE_IOCAP_ATOMIC64K] 827 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 828 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 829 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 830 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 831 ** <li> [SQLITE_IOCAP_IMMUTABLE] 832 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 833 ** <li> [SQLITE_IOCAP_SUBPAGE_READ] 834 ** </ul> 835 ** 836 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 837 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 838 ** mean that writes of blocks that are nnn bytes in size and 839 ** are aligned to an address which is an integer multiple of 840 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 841 ** that when data is appended to a file, the data is appended 842 ** first then the size of the file is extended, never the other 843 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 844 ** information is written to disk in the same order as calls 845 ** to xWrite(). 846 ** 847 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 848 ** in the unread portions of the buffer with zeros. A VFS that 849 ** fails to zero-fill short reads might seem to work. However, 850 ** failure to zero-fill short reads will eventually lead to 851 ** database corruption. 852 */ 853 typedef struct sqlite3_io_methods sqlite3_io_methods; 854 struct sqlite3_io_methods { 855 int iVersion; 856 int (*xClose)(sqlite3_file*); 857 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 858 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 859 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 860 int (*xSync)(sqlite3_file*, int flags); 861 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 862 int (*xLock)(sqlite3_file*, int); 863 int (*xUnlock)(sqlite3_file*, int); 864 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 865 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 866 int (*xSectorSize)(sqlite3_file*); 867 int (*xDeviceCharacteristics)(sqlite3_file*); 868 /* Methods above are valid for version 1 */ 869 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 870 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 871 void (*xShmBarrier)(sqlite3_file*); 872 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 873 /* Methods above are valid for version 2 */ 874 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 875 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 876 /* Methods above are valid for version 3 */ 877 /* Additional methods may be added in future releases */ 878 }; 879 880 /* 881 ** CAPI3REF: Standard File Control Opcodes 882 ** KEYWORDS: {file control opcodes} {file control opcode} 883 ** 884 ** These integer constants are opcodes for the xFileControl method 885 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 886 ** interface. 887 ** 888 ** <ul> 889 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 890 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 891 ** opcode causes the xFileControl method to write the current state of 892 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 893 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 894 ** into an integer that the pArg argument points to. 895 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 896 ** 897 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 898 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 899 ** layer a hint of how large the database file will grow to be during the 900 ** current transaction. This hint is not guaranteed to be accurate but it 901 ** is often close. The underlying VFS might choose to preallocate database 902 ** file space based on this hint in order to help writes to the database 903 ** file run faster. 904 ** 905 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 906 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 907 ** implements [sqlite3_deserialize()] to set an upper bound on the size 908 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 909 ** If the integer pointed to is negative, then it is filled in with the 910 ** current limit. Otherwise the limit is set to the larger of the value 911 ** of the integer pointed to and the current database size. The integer 912 ** pointed to is set to the new limit. 913 ** 914 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 915 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 916 ** extends and truncates the database file in chunks of a size specified 917 ** by the user. The fourth argument to [sqlite3_file_control()] should 918 ** point to an integer (type int) containing the new chunk-size to use 919 ** for the nominated database. Allocating database file space in large 920 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 921 ** improve performance on some systems. 922 ** 923 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 924 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 925 ** to the [sqlite3_file] object associated with a particular database 926 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 927 ** 928 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 929 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 930 ** to the [sqlite3_file] object associated with the journal file (either 931 ** the [rollback journal] or the [write-ahead log]) for a particular database 932 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 933 ** 934 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 935 ** The SQLITE_FCNTL_SYNC_OMITTED file-control is no longer used. 936 ** 937 ** <li>[[SQLITE_FCNTL_SYNC]] 938 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 939 ** sent to the VFS immediately before the xSync method is invoked on a 940 ** database file descriptor. Or, if the xSync method is not invoked 941 ** because the user has configured SQLite with 942 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 943 ** of the xSync method. In most cases, the pointer argument passed with 944 ** this file-control is NULL. However, if the database file is being synced 945 ** as part of a multi-database commit, the argument points to a nul-terminated 946 ** string containing the transactions super-journal file name. VFSes that 947 ** do not need this signal should silently ignore this opcode. Applications 948 ** should not call [sqlite3_file_control()] with this opcode as doing so may 949 ** disrupt the operation of the specialized VFSes that do require it. 950 ** 951 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 952 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 953 ** and sent to the VFS after a transaction has been committed immediately 954 ** but before the database is unlocked. VFSes that do not need this signal 955 ** should silently ignore this opcode. Applications should not call 956 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 957 ** operation of the specialized VFSes that do require it. 958 ** 959 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 960 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 961 ** retry counts and intervals for certain disk I/O operations for the 962 ** windows [VFS] in order to provide robustness in the presence of 963 ** anti-virus programs. By default, the windows VFS will retry file read, 964 ** file write, and file delete operations up to 10 times, with a delay 965 ** of 25 milliseconds before the first retry and with the delay increasing 966 ** by an additional 25 milliseconds with each subsequent retry. This 967 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 968 ** to be adjusted. The values are changed for all database connections 969 ** within the same process. The argument is a pointer to an array of two 970 ** integers where the first integer is the new retry count and the second 971 ** integer is the delay. If either integer is negative, then the setting 972 ** is not changed but instead the prior value of that setting is written 973 ** into the array entry, allowing the current retry settings to be 974 ** interrogated. The zDbName parameter is ignored. 975 ** 976 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 977 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 978 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 979 ** write ahead log ([WAL file]) and shared memory 980 ** files used for transaction control 981 ** are automatically deleted when the latest connection to the database 982 ** closes. Setting persistent WAL mode causes those files to persist after 983 ** close. Persisting the files is useful when other processes that do not 984 ** have write permission on the directory containing the database file want 985 ** to read the database file, as the WAL and shared memory files must exist 986 ** in order for the database to be readable. The fourth parameter to 987 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 988 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 989 ** WAL mode. If the integer is -1, then it is overwritten with the current 990 ** WAL persistence setting. 991 ** 992 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 993 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 994 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 995 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 996 ** xDeviceCharacteristics methods. The fourth parameter to 997 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 998 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 999 ** mode. If the integer is -1, then it is overwritten with the current 1000 ** zero-damage mode setting. 1001 ** 1002 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 1003 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 1004 ** a write transaction to indicate that, unless it is rolled back for some 1005 ** reason, the entire database file will be overwritten by the current 1006 ** transaction. This is used by VACUUM operations. 1007 ** 1008 ** <li>[[SQLITE_FCNTL_VFSNAME]] 1009 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 1010 ** all [VFSes] in the VFS stack. The names of all VFS shims and the 1011 ** final bottom-level VFS are written into memory obtained from 1012 ** [sqlite3_malloc()] and the result is stored in the char* variable 1013 ** that the fourth parameter of [sqlite3_file_control()] points to. 1014 ** The caller is responsible for freeing the memory when done. As with 1015 ** all file-control actions, there is no guarantee that this will actually 1016 ** do anything. Callers should initialize the char* variable to a NULL 1017 ** pointer in case this file-control is not implemented. This file-control 1018 ** is intended for diagnostic use only. 1019 ** 1020 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1021 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1022 ** [VFSes] currently in use. ^(The argument X in 1023 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1024 ** of type "[sqlite3_vfs] **". This opcode will set *X 1025 ** to a pointer to the top-level VFS.)^ 1026 ** ^When there are multiple VFS shims in the stack, this opcode finds the 1027 ** upper-most shim only. 1028 ** 1029 ** <li>[[SQLITE_FCNTL_PRAGMA]] 1030 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1031 ** file control is sent to the open [sqlite3_file] object corresponding 1032 ** to the database file to which the pragma statement refers. ^The argument 1033 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1034 ** pointers to strings (char**) in which the second element of the array 1035 ** is the name of the pragma and the third element is the argument to the 1036 ** pragma or NULL if the pragma has no argument. ^The handler for an 1037 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1038 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1039 ** or the equivalent and that string will become the result of the pragma or 1040 ** the error message if the pragma fails. ^If the 1041 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1042 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1043 ** file control returns [SQLITE_OK], then the parser assumes that the 1044 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1045 ** prepared statement if result string is NULL, or that returns a copy 1046 ** of the result string if the string is non-NULL. 1047 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1048 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1049 ** that the VFS encountered an error while handling the [PRAGMA] and the 1050 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1051 ** file control occurs at the beginning of pragma statement analysis and so 1052 ** it is able to override built-in [PRAGMA] statements. 1053 ** 1054 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1055 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1056 ** file-control may be invoked by SQLite on the database file handle 1057 ** shortly after it is opened in order to provide a custom VFS with access 1058 ** to the connection's busy-handler callback. The argument is of type (void**) 1059 ** - an array of two (void *) values. The first (void *) actually points 1060 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1061 ** busy-handler, this function should be invoked with the second (void *) in 1062 ** the array as the only argument. If it returns non-zero, then the operation 1063 ** should be retried. If it returns zero, the custom VFS should abandon the 1064 ** current operation. 1065 ** 1066 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1067 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1068 ** to have SQLite generate a 1069 ** temporary filename using the same algorithm that is followed to generate 1070 ** temporary filenames for TEMP tables and other internal uses. The 1071 ** argument should be a char** which will be filled with the filename 1072 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1073 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1074 ** 1075 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1076 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1077 ** maximum number of bytes that will be used for memory-mapped I/O. 1078 ** The argument is a pointer to a value of type sqlite3_int64 that 1079 ** is an advisory maximum number of bytes in the file to memory map. The 1080 ** pointer is overwritten with the old value. The limit is not changed if 1081 ** the value originally pointed to is negative, and so the current limit 1082 ** can be queried by passing in a pointer to a negative number. This 1083 ** file-control is used internally to implement [PRAGMA mmap_size]. 1084 ** 1085 ** <li>[[SQLITE_FCNTL_TRACE]] 1086 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1087 ** to the VFS about what the higher layers of the SQLite stack are doing. 1088 ** This file control is used by some VFS activity tracing [shims]. 1089 ** The argument is a zero-terminated string. Higher layers in the 1090 ** SQLite stack may generate instances of this file control if 1091 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1092 ** 1093 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1094 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1095 ** pointer to an integer and it writes a boolean into that integer depending 1096 ** on whether or not the file has been renamed, moved, or deleted since it 1097 ** was first opened. 1098 ** 1099 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1100 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1101 ** underlying native file handle associated with a file handle. This file 1102 ** control interprets its argument as a pointer to a native file handle and 1103 ** writes the resulting value there. 1104 ** 1105 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1106 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1107 ** opcode causes the xFileControl method to swap the file handle with the one 1108 ** pointed to by the pArg argument. This capability is used during testing 1109 ** and only needs to be supported when SQLITE_TEST is defined. 1110 ** 1111 ** <li>[[SQLITE_FCNTL_NULL_IO]] 1112 ** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor 1113 ** or file handle for the [sqlite3_file] object such that it will no longer 1114 ** read or write to the database file. 1115 ** 1116 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1117 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1118 ** be advantageous to block on the next WAL lock if the lock is not immediately 1119 ** available. The WAL subsystem issues this signal during rare 1120 ** circumstances in order to fix a problem with priority inversion. 1121 ** Applications should <em>not</em> use this file-control. 1122 ** 1123 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1124 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1125 ** VFS should return SQLITE_NOTFOUND for this opcode. 1126 ** 1127 ** <li>[[SQLITE_FCNTL_RBU]] 1128 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1129 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1130 ** this opcode. 1131 ** 1132 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1133 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1134 ** the file descriptor is placed in "batch write mode", which 1135 ** means all subsequent write operations will be deferred and done 1136 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1137 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1138 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1139 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1140 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1141 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1142 ** except for calls to the xWrite method and the xFileControl method 1143 ** with [SQLITE_FCNTL_SIZE_HINT]. 1144 ** 1145 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1146 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1147 ** operations since the previous successful call to 1148 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1149 ** This file control returns [SQLITE_OK] if and only if the writes were 1150 ** all performed successfully and have been committed to persistent storage. 1151 ** ^Regardless of whether or not it is successful, this file control takes 1152 ** the file descriptor out of batch write mode so that all subsequent 1153 ** write operations are independent. 1154 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1155 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1156 ** 1157 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1158 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1159 ** operations since the previous successful call to 1160 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1161 ** ^This file control takes the file descriptor out of batch write mode 1162 ** so that all subsequent write operations are independent. 1163 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1164 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1165 ** 1166 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1167 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1168 ** to block for up to M milliseconds before failing when attempting to 1169 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1170 ** The parameter is a pointer to a 32-bit signed integer that contains 1171 ** the value that M is to be set to. Before returning, the 32-bit signed 1172 ** integer is overwritten with the previous value of M. 1173 ** 1174 ** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]] 1175 ** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the 1176 ** VFS to block when taking a SHARED lock to connect to a wal mode database. 1177 ** This is used to implement the functionality associated with 1178 ** SQLITE_SETLK_BLOCK_ON_CONNECT. 1179 ** 1180 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1181 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1182 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1183 ** The "data version" for the pager is written into the pointer. The 1184 ** "data version" changes whenever any change occurs to the corresponding 1185 ** database file, either through SQL statements on the same database 1186 ** connection or through transactions committed by separate database 1187 ** connections possibly in other processes. The [sqlite3_total_changes()] 1188 ** interface can be used to find if any database on the connection has changed, 1189 ** but that interface responds to changes on TEMP as well as MAIN and does 1190 ** not provide a mechanism to detect changes to MAIN only. Also, the 1191 ** [sqlite3_total_changes()] interface responds to internal changes only and 1192 ** omits changes made by other database connections. The 1193 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1194 ** a single attached database that occur due to other database connections, 1195 ** but omits changes implemented by the database connection on which it is 1196 ** called. This file control is the only mechanism to detect changes that 1197 ** happen either internally or externally and that are associated with 1198 ** a particular attached database. 1199 ** 1200 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1201 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1202 ** in wal mode before the client starts to copy pages from the wal 1203 ** file to the database file. 1204 ** 1205 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1206 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1207 ** in wal mode after the client has finished copying pages from the wal 1208 ** file to the database file, but before the *-shm file is updated to 1209 ** record the fact that the pages have been checkpointed. 1210 ** 1211 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1212 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1213 ** whether or not there is a database client in another process with a wal-mode 1214 ** transaction open on the database or not. It is only available on unix. The 1215 ** (void*) argument passed with this file-control should be a pointer to a 1216 ** value of type (int). The integer value is set to 1 if the database is a wal 1217 ** mode database and there exists at least one client in another process that 1218 ** currently has an SQL transaction open on the database. It is set to 0 if 1219 ** the database is not a wal-mode db, or if there is no such connection in any 1220 ** other process. This opcode cannot be used to detect transactions opened 1221 ** by clients within the current process, only within other processes. 1222 ** 1223 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1224 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the 1225 ** [checksum VFS shim] only. 1226 ** 1227 ** <li>[[SQLITE_FCNTL_RESET_CACHE]] 1228 ** If there is currently no transaction open on the database, and the 1229 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control 1230 ** purges the contents of the in-memory page cache. If there is an open 1231 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error. 1232 ** 1233 ** <li>[[SQLITE_FCNTL_FILESTAT]] 1234 ** The [SQLITE_FCNTL_FILESTAT] opcode returns low-level diagnostic information 1235 ** about the [sqlite3_file] objects used access the database and journal files 1236 ** for the given schema. The fourth parameter to [sqlite3_file_control()] 1237 ** should be an initialized [sqlite3_str] pointer. JSON text describing 1238 ** various aspects of the sqlite3_file object is appended to the sqlite3_str. 1239 ** The SQLITE_FCNTL_FILESTAT opcode is usually a no-op, unless compile-time 1240 ** options are used to enable it. 1241 ** </ul> 1242 */ 1243 #define SQLITE_FCNTL_LOCKSTATE 1 1244 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1245 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1246 #define SQLITE_FCNTL_LAST_ERRNO 4 1247 #define SQLITE_FCNTL_SIZE_HINT 5 1248 #define SQLITE_FCNTL_CHUNK_SIZE 6 1249 #define SQLITE_FCNTL_FILE_POINTER 7 1250 #define SQLITE_FCNTL_SYNC_OMITTED 8 1251 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1252 #define SQLITE_FCNTL_PERSIST_WAL 10 1253 #define SQLITE_FCNTL_OVERWRITE 11 1254 #define SQLITE_FCNTL_VFSNAME 12 1255 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1256 #define SQLITE_FCNTL_PRAGMA 14 1257 #define SQLITE_FCNTL_BUSYHANDLER 15 1258 #define SQLITE_FCNTL_TEMPFILENAME 16 1259 #define SQLITE_FCNTL_MMAP_SIZE 18 1260 #define SQLITE_FCNTL_TRACE 19 1261 #define SQLITE_FCNTL_HAS_MOVED 20 1262 #define SQLITE_FCNTL_SYNC 21 1263 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1264 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1265 #define SQLITE_FCNTL_WAL_BLOCK 24 1266 #define SQLITE_FCNTL_ZIPVFS 25 1267 #define SQLITE_FCNTL_RBU 26 1268 #define SQLITE_FCNTL_VFS_POINTER 27 1269 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1270 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1271 #define SQLITE_FCNTL_PDB 30 1272 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1273 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1274 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1275 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1276 #define SQLITE_FCNTL_DATA_VERSION 35 1277 #define SQLITE_FCNTL_SIZE_LIMIT 36 1278 #define SQLITE_FCNTL_CKPT_DONE 37 1279 #define SQLITE_FCNTL_RESERVE_BYTES 38 1280 #define SQLITE_FCNTL_CKPT_START 39 1281 #define SQLITE_FCNTL_EXTERNAL_READER 40 1282 #define SQLITE_FCNTL_CKSM_FILE 41 1283 #define SQLITE_FCNTL_RESET_CACHE 42 1284 #define SQLITE_FCNTL_NULL_IO 43 1285 #define SQLITE_FCNTL_BLOCK_ON_CONNECT 44 1286 #define SQLITE_FCNTL_FILESTAT 45 1287 1288 /* deprecated names */ 1289 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1290 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1291 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1292 1293 1294 /* 1295 ** CAPI3REF: Mutex Handle 1296 ** 1297 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1298 ** abstract type for a mutex object. The SQLite core never looks 1299 ** at the internal representation of an [sqlite3_mutex]. It only 1300 ** deals with pointers to the [sqlite3_mutex] object. 1301 ** 1302 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1303 */ 1304 typedef struct sqlite3_mutex sqlite3_mutex; 1305 1306 /* 1307 ** CAPI3REF: Loadable Extension Thunk 1308 ** 1309 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1310 ** the third parameter to entry points of [loadable extensions]. This 1311 ** structure must be typedefed in order to work around compiler warnings 1312 ** on some platforms. 1313 */ 1314 typedef struct sqlite3_api_routines sqlite3_api_routines; 1315 1316 /* 1317 ** CAPI3REF: File Name 1318 ** 1319 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1320 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1321 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1322 ** may also be passed to special APIs such as: 1323 ** 1324 ** <ul> 1325 ** <li> sqlite3_filename_database() 1326 ** <li> sqlite3_filename_journal() 1327 ** <li> sqlite3_filename_wal() 1328 ** <li> sqlite3_uri_parameter() 1329 ** <li> sqlite3_uri_boolean() 1330 ** <li> sqlite3_uri_int64() 1331 ** <li> sqlite3_uri_key() 1332 ** </ul> 1333 */ 1334 typedef const char *sqlite3_filename; 1335 1336 /* 1337 ** CAPI3REF: OS Interface Object 1338 ** 1339 ** An instance of the sqlite3_vfs object defines the interface between 1340 ** the SQLite core and the underlying operating system. The "vfs" 1341 ** in the name of the object stands for "virtual file system". See 1342 ** the [VFS | VFS documentation] for further information. 1343 ** 1344 ** The VFS interface is sometimes extended by adding new methods onto 1345 ** the end. Each time such an extension occurs, the iVersion field 1346 ** is incremented. The iVersion value started out as 1 in 1347 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1348 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1349 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1350 ** may be appended to the sqlite3_vfs object and the iVersion value 1351 ** may increase again in future versions of SQLite. 1352 ** Note that due to an oversight, the structure 1353 ** of the sqlite3_vfs object changed in the transition from 1354 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1355 ** and yet the iVersion field was not increased. 1356 ** 1357 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1358 ** structure used by this VFS. mxPathname is the maximum length of 1359 ** a pathname in this VFS. 1360 ** 1361 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1362 ** the pNext pointer. The [sqlite3_vfs_register()] 1363 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1364 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1365 ** searches the list. Neither the application code nor the VFS 1366 ** implementation should use the pNext pointer. 1367 ** 1368 ** The pNext field is the only field in the sqlite3_vfs 1369 ** structure that SQLite will ever modify. SQLite will only access 1370 ** or modify this field while holding a particular static mutex. 1371 ** The application should never modify anything within the sqlite3_vfs 1372 ** object once the object has been registered. 1373 ** 1374 ** The zName field holds the name of the VFS module. The name must 1375 ** be unique across all VFS modules. 1376 ** 1377 ** [[sqlite3_vfs.xOpen]] 1378 ** ^SQLite guarantees that the zFilename parameter to xOpen 1379 ** is either a NULL pointer or string obtained 1380 ** from xFullPathname() with an optional suffix added. 1381 ** ^If a suffix is added to the zFilename parameter, it will 1382 ** consist of a single "-" character followed by no more than 1383 ** 11 alphanumeric and/or "-" characters. 1384 ** ^SQLite further guarantees that 1385 ** the string will be valid and unchanged until xClose() is 1386 ** called. Because of the previous sentence, 1387 ** the [sqlite3_file] can safely store a pointer to the 1388 ** filename if it needs to remember the filename for some reason. 1389 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1390 ** must invent its own temporary name for the file. ^Whenever the 1391 ** xFilename parameter is NULL it will also be the case that the 1392 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1393 ** 1394 ** The flags argument to xOpen() includes all bits set in 1395 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1396 ** or [sqlite3_open16()] is used, then flags includes at least 1397 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1398 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1399 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1400 ** 1401 ** ^(SQLite will also add one of the following flags to the xOpen() 1402 ** call, depending on the object being opened: 1403 ** 1404 ** <ul> 1405 ** <li> [SQLITE_OPEN_MAIN_DB] 1406 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1407 ** <li> [SQLITE_OPEN_TEMP_DB] 1408 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1409 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1410 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1411 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1412 ** <li> [SQLITE_OPEN_WAL] 1413 ** </ul>)^ 1414 ** 1415 ** The file I/O implementation can use the object type flags to 1416 ** change the way it deals with files. For example, an application 1417 ** that does not care about crash recovery or rollback might make 1418 ** the open of a journal file a no-op. Writes to this journal would 1419 ** also be no-ops, and any attempt to read the journal would return 1420 ** SQLITE_IOERR. Or the implementation might recognize that a database 1421 ** file will be doing page-aligned sector reads and writes in a random 1422 ** order and set up its I/O subsystem accordingly. 1423 ** 1424 ** SQLite might also add one of the following flags to the xOpen method: 1425 ** 1426 ** <ul> 1427 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1428 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1429 ** </ul> 1430 ** 1431 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1432 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1433 ** will be set for TEMP databases and their journals, transient 1434 ** databases, and subjournals. 1435 ** 1436 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1437 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1438 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1439 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1440 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1441 ** be created, and that it is an error if it already exists. 1442 ** It is <i>not</i> used to indicate the file should be opened 1443 ** for exclusive access. 1444 ** 1445 ** ^At least szOsFile bytes of memory are allocated by SQLite 1446 ** to hold the [sqlite3_file] structure passed as the third 1447 ** argument to xOpen. The xOpen method does not have to 1448 ** allocate the structure; it should just fill it in. Note that 1449 ** the xOpen method must set the sqlite3_file.pMethods to either 1450 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1451 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1452 ** element will be valid after xOpen returns regardless of the success 1453 ** or failure of the xOpen call. 1454 ** 1455 ** [[sqlite3_vfs.xAccess]] 1456 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1457 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1458 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1459 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1460 ** flag is never actually used and is not implemented in the built-in 1461 ** VFSes of SQLite. The file is named by the second argument and can be a 1462 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1463 ** non-zero error code if there is an I/O error or if the name of 1464 ** the file given in the second argument is illegal. If SQLITE_OK 1465 ** is returned, then non-zero or zero is written into *pResOut to indicate 1466 ** whether or not the file is accessible. 1467 ** 1468 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1469 ** output buffer xFullPathname. The exact size of the output buffer 1470 ** is also passed as a parameter to both methods. If the output buffer 1471 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1472 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1473 ** to prevent this by setting mxPathname to a sufficiently large value. 1474 ** 1475 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1476 ** interfaces are not strictly a part of the filesystem, but they are 1477 ** included in the VFS structure for completeness. 1478 ** The xRandomness() function attempts to return nBytes bytes 1479 ** of good-quality randomness into zOut. The return value is 1480 ** the actual number of bytes of randomness obtained. 1481 ** The xSleep() method causes the calling thread to sleep for at 1482 ** least the number of microseconds given. ^The xCurrentTime() 1483 ** method returns a Julian Day Number for the current date and time as 1484 ** a floating point value. 1485 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1486 ** Day Number multiplied by 86400000 (the number of milliseconds in 1487 ** a 24-hour day). 1488 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1489 ** date and time if that method is available (if iVersion is 2 or 1490 ** greater and the function pointer is not NULL) and will fall back 1491 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1492 ** 1493 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1494 ** are not used by the SQLite core. These optional interfaces are provided 1495 ** by some VFSes to facilitate testing of the VFS code. By overriding 1496 ** system calls with functions under its control, a test program can 1497 ** simulate faults and error conditions that would otherwise be difficult 1498 ** or impossible to induce. The set of system calls that can be overridden 1499 ** varies from one VFS to another, and from one version of the same VFS to the 1500 ** next. Applications that use these interfaces must be prepared for any 1501 ** or all of these interfaces to be NULL or for their behavior to change 1502 ** from one release to the next. Applications must not attempt to access 1503 ** any of these methods if the iVersion of the VFS is less than 3. 1504 */ 1505 typedef struct sqlite3_vfs sqlite3_vfs; 1506 typedef void (*sqlite3_syscall_ptr)(void); 1507 struct sqlite3_vfs { 1508 int iVersion; /* Structure version number (currently 3) */ 1509 int szOsFile; /* Size of subclassed sqlite3_file */ 1510 int mxPathname; /* Maximum file pathname length */ 1511 sqlite3_vfs *pNext; /* Next registered VFS */ 1512 const char *zName; /* Name of this virtual file system */ 1513 void *pAppData; /* Pointer to application-specific data */ 1514 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1515 int flags, int *pOutFlags); 1516 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1517 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1518 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1519 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1520 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1521 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1522 void (*xDlClose)(sqlite3_vfs*, void*); 1523 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1524 int (*xSleep)(sqlite3_vfs*, int microseconds); 1525 int (*xCurrentTime)(sqlite3_vfs*, double*); 1526 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1527 /* 1528 ** The methods above are in version 1 of the sqlite_vfs object 1529 ** definition. Those that follow are added in version 2 or later 1530 */ 1531 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1532 /* 1533 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1534 ** Those below are for version 3 and greater. 1535 */ 1536 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1537 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1538 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1539 /* 1540 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1541 ** New fields may be appended in future versions. The iVersion 1542 ** value will increment whenever this happens. 1543 */ 1544 }; 1545 1546 /* 1547 ** CAPI3REF: Flags for the xAccess VFS method 1548 ** 1549 ** These integer constants can be used as the third parameter to 1550 ** the xAccess method of an [sqlite3_vfs] object. They determine 1551 ** what kind of permissions the xAccess method is looking for. 1552 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1553 ** simply checks whether the file exists. 1554 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1555 ** checks whether the named directory is both readable and writable 1556 ** (in other words, if files can be added, removed, and renamed within 1557 ** the directory). 1558 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1559 ** [temp_store_directory pragma], though this could change in a future 1560 ** release of SQLite. 1561 ** With SQLITE_ACCESS_READ, the xAccess method 1562 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1563 ** currently unused, though it might be used in a future release of 1564 ** SQLite. 1565 */ 1566 #define SQLITE_ACCESS_EXISTS 0 1567 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1568 #define SQLITE_ACCESS_READ 2 /* Unused */ 1569 1570 /* 1571 ** CAPI3REF: Flags for the xShmLock VFS method 1572 ** 1573 ** These integer constants define the various locking operations 1574 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1575 ** following are the only legal combinations of flags to the 1576 ** xShmLock method: 1577 ** 1578 ** <ul> 1579 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1580 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1581 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1582 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1583 ** </ul> 1584 ** 1585 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1586 ** was given on the corresponding lock. 1587 ** 1588 ** The xShmLock method can transition between unlocked and SHARED or 1589 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1590 ** and EXCLUSIVE. 1591 */ 1592 #define SQLITE_SHM_UNLOCK 1 1593 #define SQLITE_SHM_LOCK 2 1594 #define SQLITE_SHM_SHARED 4 1595 #define SQLITE_SHM_EXCLUSIVE 8 1596 1597 /* 1598 ** CAPI3REF: Maximum xShmLock index 1599 ** 1600 ** The xShmLock method on [sqlite3_io_methods] may use values 1601 ** between 0 and this upper bound as its "offset" argument. 1602 ** The SQLite core will never attempt to acquire or release a 1603 ** lock outside of this range 1604 */ 1605 #define SQLITE_SHM_NLOCK 8 1606 1607 1608 /* 1609 ** CAPI3REF: Initialize The SQLite Library 1610 ** 1611 ** ^The sqlite3_initialize() routine initializes the 1612 ** SQLite library. ^The sqlite3_shutdown() routine 1613 ** deallocates any resources that were allocated by sqlite3_initialize(). 1614 ** These routines are designed to aid in process initialization and 1615 ** shutdown on embedded systems. Workstation applications using 1616 ** SQLite normally do not need to invoke either of these routines. 1617 ** 1618 ** A call to sqlite3_initialize() is an "effective" call if it is 1619 ** the first time sqlite3_initialize() is invoked during the lifetime of 1620 ** the process, or if it is the first time sqlite3_initialize() is invoked 1621 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1622 ** of sqlite3_initialize() does any initialization. All other calls 1623 ** are harmless no-ops.)^ 1624 ** 1625 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1626 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1627 ** an effective call to sqlite3_shutdown() does any deinitialization. 1628 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1629 ** 1630 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1631 ** is not. The sqlite3_shutdown() interface must only be called from a 1632 ** single thread. All open [database connections] must be closed and all 1633 ** other SQLite resources must be deallocated prior to invoking 1634 ** sqlite3_shutdown(). 1635 ** 1636 ** Among other things, ^sqlite3_initialize() will invoke 1637 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1638 ** will invoke sqlite3_os_end(). 1639 ** 1640 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1641 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1642 ** the library (perhaps it is unable to allocate a needed resource such 1643 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1644 ** 1645 ** ^The sqlite3_initialize() routine is called internally by many other 1646 ** SQLite interfaces so that an application usually does not need to 1647 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1648 ** calls sqlite3_initialize() so the SQLite library will be automatically 1649 ** initialized when [sqlite3_open()] is called if it has not been initialized 1650 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1651 ** compile-time option, then the automatic calls to sqlite3_initialize() 1652 ** are omitted and the application must call sqlite3_initialize() directly 1653 ** prior to using any other SQLite interface. For maximum portability, 1654 ** it is recommended that applications always invoke sqlite3_initialize() 1655 ** directly prior to using any other SQLite interface. Future releases 1656 ** of SQLite may require this. In other words, the behavior exhibited 1657 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1658 ** default behavior in some future release of SQLite. 1659 ** 1660 ** The sqlite3_os_init() routine does operating-system specific 1661 ** initialization of the SQLite library. The sqlite3_os_end() 1662 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1663 ** performed by these routines include allocation or deallocation 1664 ** of static resources, initialization of global variables, 1665 ** setting up a default [sqlite3_vfs] module, or setting up 1666 ** a default configuration using [sqlite3_config()]. 1667 ** 1668 ** The application should never invoke either sqlite3_os_init() 1669 ** or sqlite3_os_end() directly. The application should only invoke 1670 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1671 ** interface is called automatically by sqlite3_initialize() and 1672 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1673 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1674 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1675 ** When [custom builds | built for other platforms] 1676 ** (using the [SQLITE_OS_OTHER=1] compile-time 1677 ** option) the application must supply a suitable implementation for 1678 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1679 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1680 ** must return [SQLITE_OK] on success and some other [error code] upon 1681 ** failure. 1682 */ 1683 SQLITE_API int sqlite3_initialize(void); 1684 SQLITE_API int sqlite3_shutdown(void); 1685 SQLITE_API int sqlite3_os_init(void); 1686 SQLITE_API int sqlite3_os_end(void); 1687 1688 /* 1689 ** CAPI3REF: Configuring The SQLite Library 1690 ** 1691 ** The sqlite3_config() interface is used to make global configuration 1692 ** changes to SQLite in order to tune SQLite to the specific needs of 1693 ** the application. The default configuration is recommended for most 1694 ** applications and so this routine is usually not necessary. It is 1695 ** provided to support rare applications with unusual needs. 1696 ** 1697 ** <b>The sqlite3_config() interface is not threadsafe. The application 1698 ** must ensure that no other SQLite interfaces are invoked by other 1699 ** threads while sqlite3_config() is running.</b> 1700 ** 1701 ** The first argument to sqlite3_config() is an integer 1702 ** [configuration option] that determines 1703 ** what property of SQLite is to be configured. Subsequent arguments 1704 ** vary depending on the [configuration option] 1705 ** in the first argument. 1706 ** 1707 ** For most configuration options, the sqlite3_config() interface 1708 ** may only be invoked prior to library initialization using 1709 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1710 ** The exceptional configuration options that may be invoked at any time 1711 ** are called "anytime configuration options". 1712 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1713 ** [sqlite3_shutdown()] with a first argument that is not an anytime 1714 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE. 1715 ** Note, however, that ^sqlite3_config() can be called as part of the 1716 ** implementation of an application-defined [sqlite3_os_init()]. 1717 ** 1718 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1719 ** ^If the option is unknown or SQLite is unable to set the option 1720 ** then this routine returns a non-zero [error code]. 1721 */ 1722 SQLITE_API int sqlite3_config(int, ...); 1723 1724 /* 1725 ** CAPI3REF: Configure database connections 1726 ** METHOD: sqlite3 1727 ** 1728 ** The sqlite3_db_config() interface is used to make configuration 1729 ** changes to a [database connection]. The interface is similar to 1730 ** [sqlite3_config()] except that the changes apply to a single 1731 ** [database connection] (specified in the first argument). 1732 ** 1733 ** The second argument to sqlite3_db_config(D,V,...) is the 1734 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1735 ** that indicates what aspect of the [database connection] is being configured. 1736 ** Subsequent arguments vary depending on the configuration verb. 1737 ** 1738 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1739 ** the call is considered successful. 1740 */ 1741 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1742 1743 /* 1744 ** CAPI3REF: Memory Allocation Routines 1745 ** 1746 ** An instance of this object defines the interface between SQLite 1747 ** and low-level memory allocation routines. 1748 ** 1749 ** This object is used in only one place in the SQLite interface. 1750 ** A pointer to an instance of this object is the argument to 1751 ** [sqlite3_config()] when the configuration option is 1752 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1753 ** By creating an instance of this object 1754 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1755 ** during configuration, an application can specify an alternative 1756 ** memory allocation subsystem for SQLite to use for all of its 1757 ** dynamic memory needs. 1758 ** 1759 ** Note that SQLite comes with several [built-in memory allocators] 1760 ** that are perfectly adequate for the overwhelming majority of applications 1761 ** and that this object is only useful to a tiny minority of applications 1762 ** with specialized memory allocation requirements. This object is 1763 ** also used during testing of SQLite in order to specify an alternative 1764 ** memory allocator that simulates memory out-of-memory conditions in 1765 ** order to verify that SQLite recovers gracefully from such 1766 ** conditions. 1767 ** 1768 ** The xMalloc, xRealloc, and xFree methods must work like the 1769 ** malloc(), realloc() and free() functions from the standard C library. 1770 ** ^SQLite guarantees that the second argument to 1771 ** xRealloc is always a value returned by a prior call to xRoundup. 1772 ** 1773 ** xSize should return the allocated size of a memory allocation 1774 ** previously obtained from xMalloc or xRealloc. The allocated size 1775 ** is always at least as big as the requested size but may be larger. 1776 ** 1777 ** The xRoundup method returns what would be the allocated size of 1778 ** a memory allocation given a particular requested size. Most memory 1779 ** allocators round up memory allocations at least to the next multiple 1780 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1781 ** Every memory allocation request coming in through [sqlite3_malloc()] 1782 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1783 ** that causes the corresponding memory allocation to fail. 1784 ** 1785 ** The xInit method initializes the memory allocator. For example, 1786 ** it might allocate any required mutexes or initialize internal data 1787 ** structures. The xShutdown method is invoked (indirectly) by 1788 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1789 ** by xInit. The pAppData pointer is used as the only parameter to 1790 ** xInit and xShutdown. 1791 ** 1792 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1793 ** the xInit method, so the xInit method need not be threadsafe. The 1794 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1795 ** not need to be threadsafe either. For all other methods, SQLite 1796 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1797 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1798 ** it is by default) and so the methods are automatically serialized. 1799 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1800 ** methods must be threadsafe or else make their own arrangements for 1801 ** serialization. 1802 ** 1803 ** SQLite will never invoke xInit() more than once without an intervening 1804 ** call to xShutdown(). 1805 */ 1806 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1807 struct sqlite3_mem_methods { 1808 void *(*xMalloc)(int); /* Memory allocation function */ 1809 void (*xFree)(void*); /* Free a prior allocation */ 1810 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1811 int (*xSize)(void*); /* Return the size of an allocation */ 1812 int (*xRoundup)(int); /* Round up request size to allocation size */ 1813 int (*xInit)(void*); /* Initialize the memory allocator */ 1814 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1815 void *pAppData; /* Argument to xInit() and xShutdown() */ 1816 }; 1817 1818 /* 1819 ** CAPI3REF: Configuration Options 1820 ** KEYWORDS: {configuration option} 1821 ** 1822 ** These constants are the available integer configuration options that 1823 ** can be passed as the first argument to the [sqlite3_config()] interface. 1824 ** 1825 ** Most of the configuration options for sqlite3_config() 1826 ** will only work if invoked prior to [sqlite3_initialize()] or after 1827 ** [sqlite3_shutdown()]. The few exceptions to this rule are called 1828 ** "anytime configuration options". 1829 ** ^Calling [sqlite3_config()] with a first argument that is not an 1830 ** anytime configuration option in between calls to [sqlite3_initialize()] and 1831 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE. 1832 ** 1833 ** The set of anytime configuration options can change (by insertions 1834 ** and/or deletions) from one release of SQLite to the next. 1835 ** As of SQLite version 3.42.0, the complete set of anytime configuration 1836 ** options is: 1837 ** <ul> 1838 ** <li> SQLITE_CONFIG_LOG 1839 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ 1840 ** </ul> 1841 ** 1842 ** New configuration options may be added in future releases of SQLite. 1843 ** Existing configuration options might be discontinued. Applications 1844 ** should check the return code from [sqlite3_config()] to make sure that 1845 ** the call worked. The [sqlite3_config()] interface will return a 1846 ** non-zero [error code] if a discontinued or unsupported configuration option 1847 ** is invoked. 1848 ** 1849 ** <dl> 1850 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1851 ** <dd>There are no arguments to this option. ^This option sets the 1852 ** [threading mode] to Single-thread. In other words, it disables 1853 ** all mutexing and puts SQLite into a mode where it can only be used 1854 ** by a single thread. ^If SQLite is compiled with 1855 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1856 ** it is not possible to change the [threading mode] from its default 1857 ** value of Single-thread and so [sqlite3_config()] will return 1858 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1859 ** configuration option.</dd> 1860 ** 1861 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1862 ** <dd>There are no arguments to this option. ^This option sets the 1863 ** [threading mode] to Multi-thread. In other words, it disables 1864 ** mutexing on [database connection] and [prepared statement] objects. 1865 ** The application is responsible for serializing access to 1866 ** [database connections] and [prepared statements]. But other mutexes 1867 ** are enabled so that SQLite will be safe to use in a multi-threaded 1868 ** environment as long as no two threads attempt to use the same 1869 ** [database connection] at the same time. ^If SQLite is compiled with 1870 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1871 ** it is not possible to set the Multi-thread [threading mode] and 1872 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1873 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1874 ** 1875 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1876 ** <dd>There are no arguments to this option. ^This option sets the 1877 ** [threading mode] to Serialized. In other words, this option enables 1878 ** all mutexes including the recursive 1879 ** mutexes on [database connection] and [prepared statement] objects. 1880 ** In this mode (which is the default when SQLite is compiled with 1881 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1882 ** to [database connections] and [prepared statements] so that the 1883 ** application is free to use the same [database connection] or the 1884 ** same [prepared statement] in different threads at the same time. 1885 ** ^If SQLite is compiled with 1886 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1887 ** it is not possible to set the Serialized [threading mode] and 1888 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1889 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1890 ** 1891 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1892 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1893 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1894 ** The argument specifies 1895 ** alternative low-level memory allocation routines to be used in place of 1896 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1897 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1898 ** before the [sqlite3_config()] call returns.</dd> 1899 ** 1900 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1901 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1902 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1903 ** The [sqlite3_mem_methods] 1904 ** structure is filled with the currently defined memory allocation routines.)^ 1905 ** This option can be used to overload the default memory allocation 1906 ** routines with a wrapper that simulates memory allocation failure or 1907 ** tracks memory usage, for example. </dd> 1908 ** 1909 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1910 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes a single argument of 1911 ** type int, interpreted as a boolean, which if true provides a hint to 1912 ** SQLite that it should avoid large memory allocations if possible. 1913 ** SQLite will run faster if it is free to make large memory allocations, 1914 ** but some applications might prefer to run slower in exchange for 1915 ** guarantees about memory fragmentation that are possible if large 1916 ** allocations are avoided. This hint is normally off. 1917 ** </dd> 1918 ** 1919 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1920 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes a single argument of type int, 1921 ** interpreted as a boolean, which enables or disables the collection of 1922 ** memory allocation statistics. ^(When memory allocation statistics are 1923 ** disabled, the following SQLite interfaces become non-operational: 1924 ** <ul> 1925 ** <li> [sqlite3_hard_heap_limit64()] 1926 ** <li> [sqlite3_memory_used()] 1927 ** <li> [sqlite3_memory_highwater()] 1928 ** <li> [sqlite3_soft_heap_limit64()] 1929 ** <li> [sqlite3_status64()] 1930 ** </ul>)^ 1931 ** ^Memory allocation statistics are enabled by default unless SQLite is 1932 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1933 ** allocation statistics are disabled by default. 1934 ** </dd> 1935 ** 1936 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1937 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1938 ** </dd> 1939 ** 1940 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1941 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1942 ** that SQLite can use for the database page cache with the default page 1943 ** cache implementation. 1944 ** This configuration option is a no-op if an application-defined page 1945 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1946 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1947 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1948 ** and the number of cache lines (N). 1949 ** The sz argument should be the size of the largest database page 1950 ** (a power of two between 512 and 65536) plus some extra bytes for each 1951 ** page header. ^The number of extra bytes needed by the page header 1952 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1953 ** ^It is harmless, apart from the wasted memory, 1954 ** for the sz parameter to be larger than necessary. The pMem 1955 ** argument must be either a NULL pointer or a pointer to an 8-byte 1956 ** aligned block of memory of at least sz*N bytes, otherwise 1957 ** subsequent behavior is undefined. 1958 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1959 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1960 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1961 ** is exhausted. 1962 ** ^If pMem is NULL and N is non-zero, then each database connection 1963 ** does an initial bulk allocation for page cache memory 1964 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1965 ** of -1024*N bytes if N is negative. ^If additional 1966 ** page cache memory is needed beyond what is provided by the initial 1967 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1968 ** additional cache line. </dd> 1969 ** 1970 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1971 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1972 ** that SQLite will use for all of its dynamic memory allocation needs 1973 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1974 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1975 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1976 ** [SQLITE_ERROR] if invoked otherwise. 1977 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1978 ** An 8-byte aligned pointer to the memory, 1979 ** the number of bytes in the memory buffer, and the minimum allocation size. 1980 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1981 ** to using its default memory allocator (the system malloc() implementation), 1982 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1983 ** memory pointer is not NULL then the alternative memory 1984 ** allocator is engaged to handle all of SQLites memory allocation needs. 1985 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1986 ** boundary or subsequent behavior of SQLite will be undefined. 1987 ** The minimum allocation size is capped at 2**12. Reasonable values 1988 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1989 ** 1990 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1991 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1992 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1993 ** The argument specifies alternative low-level mutex routines to be used 1994 ** in place of the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1995 ** the content of the [sqlite3_mutex_methods] structure before the call to 1996 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1997 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1998 ** the entire mutexing subsystem is omitted from the build and hence calls to 1999 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 2000 ** return [SQLITE_ERROR].</dd> 2001 ** 2002 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 2003 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 2004 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 2005 ** [sqlite3_mutex_methods] 2006 ** structure is filled with the currently defined mutex routines.)^ 2007 ** This option can be used to overload the default mutex allocation 2008 ** routines with a wrapper used to track mutex usage for performance 2009 ** profiling or testing, for example. ^If SQLite is compiled with 2010 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 2011 ** the entire mutexing subsystem is omitted from the build and hence calls to 2012 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 2013 ** return [SQLITE_ERROR].</dd> 2014 ** 2015 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 2016 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 2017 ** the default size of [lookaside memory] on each [database connection]. 2018 ** The first argument is the 2019 ** size of each lookaside buffer slot ("sz") and the second is the number of 2020 ** slots allocated to each database connection ("cnt").)^ 2021 ** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size. 2022 ** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can 2023 ** be used to change the lookaside configuration on individual connections.)^ 2024 ** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the 2025 ** default lookaside configuration at compile-time. 2026 ** </dd> 2027 ** 2028 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 2029 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 2030 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 2031 ** the interface to a custom page cache implementation.)^ 2032 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 2033 ** 2034 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 2035 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 2036 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies off 2037 ** the current page cache implementation into that object.)^ </dd> 2038 ** 2039 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 2040 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 2041 ** global [error log]. 2042 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 2043 ** function with a call signature of void(*)(void*,int,const char*), 2044 ** and a pointer to void. ^If the function pointer is not NULL, it is 2045 ** invoked by [sqlite3_log()] to process each logging event. ^If the 2046 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 2047 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 2048 ** passed through as the first parameter to the application-defined logger 2049 ** function whenever that function is invoked. ^The second parameter to 2050 ** the logger function is a copy of the first parameter to the corresponding 2051 ** [sqlite3_log()] call and is intended to be a [result code] or an 2052 ** [extended result code]. ^The third parameter passed to the logger is 2053 ** a log message after formatting via [sqlite3_snprintf()]. 2054 ** The SQLite logging interface is not reentrant; the logger function 2055 ** supplied by the application must not invoke any SQLite interface. 2056 ** In a multi-threaded application, the application-defined logger 2057 ** function must be threadsafe. </dd> 2058 ** 2059 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 2060 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 2061 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 2062 ** then URI handling is globally disabled.)^ ^If URI handling is globally 2063 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 2064 ** [sqlite3_open16()] or 2065 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 2066 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 2067 ** connection is opened. ^If it is globally disabled, filenames are 2068 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 2069 ** database connection is opened. ^(By default, URI handling is globally 2070 ** disabled. The default value may be changed by compiling with the 2071 ** [SQLITE_USE_URI] symbol defined.)^ 2072 ** 2073 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2074 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2075 ** argument which is interpreted as a boolean in order to enable or disable 2076 ** the use of covering indices for full table scans in the query optimizer. 2077 ** ^The default setting is determined 2078 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2079 ** if that compile-time option is omitted. 2080 ** The ability to disable the use of covering indices for full table scans 2081 ** is because some incorrectly coded legacy applications might malfunction 2082 ** when the optimization is enabled. Providing the ability to 2083 ** disable the optimization allows the older, buggy application code to work 2084 ** without change even with newer versions of SQLite. 2085 ** 2086 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2087 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2088 ** <dd> These options are obsolete and should not be used by new code. 2089 ** They are retained for backwards compatibility but are now no-ops. 2090 ** </dd> 2091 ** 2092 ** [[SQLITE_CONFIG_SQLLOG]] 2093 ** <dt>SQLITE_CONFIG_SQLLOG 2094 ** <dd>This option is only available if sqlite is compiled with the 2095 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2096 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2097 ** The second should be of type (void*). The callback is invoked by the library 2098 ** in three separate circumstances, identified by the value passed as the 2099 ** fourth parameter. If the fourth parameter is 0, then the database connection 2100 ** passed as the second argument has just been opened. The third argument 2101 ** points to a buffer containing the name of the main database file. If the 2102 ** fourth parameter is 1, then the SQL statement that the third parameter 2103 ** points to has just been executed. Or, if the fourth parameter is 2, then 2104 ** the connection being passed as the second parameter is being closed. The 2105 ** third parameter is passed NULL In this case. An example of using this 2106 ** configuration option can be seen in the "test_sqllog.c" source file in 2107 ** the canonical SQLite source tree.</dd> 2108 ** 2109 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2110 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2111 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2112 ** that are the default mmap size limit (the default setting for 2113 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2114 ** ^The default setting can be overridden by each database connection using 2115 ** either the [PRAGMA mmap_size] command, or by using the 2116 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2117 ** will be silently truncated if necessary so that it does not exceed the 2118 ** compile-time maximum mmap size set by the 2119 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2120 ** ^If either argument to this option is negative, then that argument is 2121 ** changed to its compile-time default. 2122 ** 2123 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2124 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2125 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2126 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2127 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2128 ** that specifies the maximum size of the created heap. 2129 ** 2130 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2131 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2132 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2133 ** is a pointer to an integer and writes into that integer the number of extra 2134 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2135 ** The amount of extra space required can change depending on the compiler, 2136 ** target platform, and SQLite version. 2137 ** 2138 ** [[SQLITE_CONFIG_PMASZ]] 2139 ** <dt>SQLITE_CONFIG_PMASZ 2140 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2141 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2142 ** sorter to that integer. The default minimum PMA Size is set by the 2143 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2144 ** to help with sort operations when multithreaded sorting 2145 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2146 ** to be sorted exceeds the page size times the minimum of the 2147 ** [PRAGMA cache_size] setting and this value. 2148 ** 2149 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2150 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2151 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2152 ** becomes the [statement journal] spill-to-disk threshold. 2153 ** [Statement journals] are held in memory until their size (in bytes) 2154 ** exceeds this threshold, at which point they are written to disk. 2155 ** Or if the threshold is -1, statement journals are always held 2156 ** exclusively in memory. 2157 ** Since many statement journals never become large, setting the spill 2158 ** threshold to a value such as 64KiB can greatly reduce the amount of 2159 ** I/O required to support statement rollback. 2160 ** The default value for this setting is controlled by the 2161 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2162 ** 2163 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2164 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2165 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2166 ** of type (int) - the new value of the sorter-reference size threshold. 2167 ** Usually, when SQLite uses an external sort to order records according 2168 ** to an ORDER BY clause, all fields required by the caller are present in the 2169 ** sorted records. However, if SQLite determines based on the declared type 2170 ** of a table column that its values are likely to be very large - larger 2171 ** than the configured sorter-reference size threshold - then a reference 2172 ** is stored in each sorted record and the required column values loaded 2173 ** from the database as records are returned in sorted order. The default 2174 ** value for this option is to never use this optimization. Specifying a 2175 ** negative value for this option restores the default behavior. 2176 ** This option is only available if SQLite is compiled with the 2177 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2178 ** 2179 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2180 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2181 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2182 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2183 ** database created using [sqlite3_deserialize()]. This default maximum 2184 ** size can be adjusted up or down for individual databases using the 2185 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2186 ** configuration setting is never used, then the default maximum is determined 2187 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2188 ** compile-time option is not set, then the default maximum is 1073741824. 2189 ** 2190 ** [[SQLITE_CONFIG_ROWID_IN_VIEW]] 2191 ** <dt>SQLITE_CONFIG_ROWID_IN_VIEW 2192 ** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability 2193 ** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is 2194 ** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability 2195 ** defaults to on. This configuration option queries the current setting or 2196 ** changes the setting to off or on. The argument is a pointer to an integer. 2197 ** If that integer initially holds a value of 1, then the ability for VIEWs to 2198 ** have ROWIDs is activated. If the integer initially holds zero, then the 2199 ** ability is deactivated. Any other initial value for the integer leaves the 2200 ** setting unchanged. After changes, if any, the integer is written with 2201 ** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite 2202 ** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and 2203 ** recommended case) then the integer is always filled with zero, regardless 2204 ** if its initial value. 2205 ** </dl> 2206 */ 2207 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2208 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2209 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2210 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2211 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2212 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2213 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2214 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2215 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2216 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2217 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2218 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2219 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2220 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2221 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2222 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2223 #define SQLITE_CONFIG_URI 17 /* int */ 2224 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2225 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2226 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2227 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2228 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2229 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2230 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2231 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2232 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2233 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2234 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2235 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2236 #define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */ 2237 2238 /* 2239 ** CAPI3REF: Database Connection Configuration Options 2240 ** 2241 ** These constants are the available integer configuration options that 2242 ** can be passed as the second parameter to the [sqlite3_db_config()] interface. 2243 ** 2244 ** The [sqlite3_db_config()] interface is a var-args function. It takes a 2245 ** variable number of parameters, though always at least two. The number of 2246 ** parameters passed into sqlite3_db_config() depends on which of these 2247 ** constants is given as the second parameter. This documentation page 2248 ** refers to parameters beyond the second as "arguments". Thus, when this 2249 ** page says "the N-th argument" it means "the N-th parameter past the 2250 ** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()". 2251 ** 2252 ** New configuration options may be added in future releases of SQLite. 2253 ** Existing configuration options might be discontinued. Applications 2254 ** should check the return code from [sqlite3_db_config()] to make sure that 2255 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2256 ** non-zero [error code] if a discontinued or unsupported configuration option 2257 ** is invoked. 2258 ** 2259 ** <dl> 2260 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2261 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2262 ** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the 2263 ** configuration of the [lookaside memory allocator] within a database 2264 ** connection. 2265 ** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i> 2266 ** in the [DBCONFIG arguments|usual format]. 2267 ** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two, 2268 ** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE 2269 ** should have a total of five parameters. 2270 ** <ol> 2271 ** <li><p>The first argument ("buf") is a 2272 ** pointer to a memory buffer to use for lookaside memory. 2273 ** The first argument may be NULL in which case SQLite will allocate the 2274 ** lookaside buffer itself using [sqlite3_malloc()]. 2275 ** <li><P>The second argument ("sz") is the 2276 ** size of each lookaside buffer slot. Lookaside is disabled if "sz" 2277 ** is less than 8. The "sz" argument should be a multiple of 8 less than 2278 ** 65536. If "sz" does not meet this constraint, it is reduced in size until 2279 ** it does. 2280 ** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled 2281 ** if "cnt"is less than 1. The "cnt" value will be reduced, if necessary, so 2282 ** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt" 2283 ** parameter is usually chosen so that the product of "sz" and "cnt" is less 2284 ** than 1,000,000. 2285 ** </ol> 2286 ** <p>If the "buf" argument is not NULL, then it must 2287 ** point to a memory buffer with a size that is greater than 2288 ** or equal to the product of "sz" and "cnt". 2289 ** The buffer must be aligned to an 8-byte boundary. 2290 ** The lookaside memory 2291 ** configuration for a database connection can only be changed when that 2292 ** connection is not currently using lookaside memory, or in other words 2293 ** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero. 2294 ** Any attempt to change the lookaside memory configuration when lookaside 2295 ** memory is in use leaves the configuration unchanged and returns 2296 ** [SQLITE_BUSY]. 2297 ** If the "buf" argument is NULL and an attempt 2298 ** to allocate memory based on "sz" and "cnt" fails, then 2299 ** lookaside is silently disabled. 2300 ** <p> 2301 ** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the 2302 ** default lookaside configuration at initialization. The 2303 ** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside 2304 ** configuration at compile-time. Typical values for lookaside are 1200 for 2305 ** "sz" and 40 to 100 for "cnt". 2306 ** </dd> 2307 ** 2308 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2309 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2310 ** <dd> ^This option is used to enable or disable the enforcement of 2311 ** [foreign key constraints]. This is the same setting that is 2312 ** enabled or disabled by the [PRAGMA foreign_keys] statement. 2313 ** The first argument is an integer which is 0 to disable FK enforcement, 2314 ** positive to enable FK enforcement or negative to leave FK enforcement 2315 ** unchanged. The second parameter is a pointer to an integer into which 2316 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2317 ** following this call. The second parameter may be a NULL pointer, in 2318 ** which case the FK enforcement setting is not reported back. </dd> 2319 ** 2320 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2321 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2322 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2323 ** There should be two additional arguments. 2324 ** The first argument is an integer which is 0 to disable triggers, 2325 ** positive to enable triggers or negative to leave the setting unchanged. 2326 ** The second parameter is a pointer to an integer into which 2327 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2328 ** following this call. The second parameter may be a NULL pointer, in 2329 ** which case the trigger setting is not reported back. 2330 ** 2331 ** <p>Originally this option disabled all triggers. ^(However, since 2332 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2333 ** this option is off. So, in other words, this option now only disables 2334 ** triggers in the main database schema or in the schemas of [ATTACH]-ed 2335 ** databases.)^ </dd> 2336 ** 2337 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2338 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2339 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2340 ** There must be two additional arguments. 2341 ** The first argument is an integer which is 0 to disable views, 2342 ** positive to enable views or negative to leave the setting unchanged. 2343 ** The second parameter is a pointer to an integer into which 2344 ** is written 0 or 1 to indicate whether views are disabled or enabled 2345 ** following this call. The second parameter may be a NULL pointer, in 2346 ** which case the view setting is not reported back. 2347 ** 2348 ** <p>Originally this option disabled all views. ^(However, since 2349 ** SQLite version 3.35.0, TEMP views are still allowed even if 2350 ** this option is off. So, in other words, this option now only disables 2351 ** views in the main database schema or in the schemas of ATTACH-ed 2352 ** databases.)^ </dd> 2353 ** 2354 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2355 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2356 ** <dd> ^This option is used to enable or disable using the 2357 ** [fts3_tokenizer()] function - part of the [FTS3] full-text search engine 2358 ** extension - without using bound parameters as the parameters. Doing so 2359 ** is disabled by default. There must be two additional arguments. The first 2360 ** argument is an integer. If it is passed 0, then using fts3_tokenizer() 2361 ** without bound parameters is disabled. If it is passed a positive value, 2362 ** then calling fts3_tokenizer without bound parameters is enabled. If it 2363 ** is passed a negative value, this setting is not modified - this can be 2364 ** used to query for the current setting. The second parameter is a pointer 2365 ** to an integer into which is written 0 or 1 to indicate the current value 2366 ** of this setting (after it is modified, if applicable). The second 2367 ** parameter may be a NULL pointer, in which case the value of the setting 2368 ** is not reported back. Refer to [FTS3] documentation for further details. 2369 ** </dd> 2370 ** 2371 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2372 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2373 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2374 ** interface independently of the [load_extension()] SQL function. 2375 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2376 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2377 ** There must be two additional arguments. 2378 ** When the first argument to this interface is 1, then only the C-API is 2379 ** enabled and the SQL function remains disabled. If the first argument to 2380 ** this interface is 0, then both the C-API and the SQL function are disabled. 2381 ** If the first argument is -1, then no changes are made to the state of either 2382 ** the C-API or the SQL function. 2383 ** The second parameter is a pointer to an integer into which 2384 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2385 ** is disabled or enabled following this call. The second parameter may 2386 ** be a NULL pointer, in which case the new setting is not reported back. 2387 ** </dd> 2388 ** 2389 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2390 ** <dd> ^This option is used to change the name of the "main" database 2391 ** schema. This option does not follow the 2392 ** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format]. 2393 ** This option takes exactly one additional argument so that the 2394 ** [sqlite3_db_config()] call has a total of three parameters. The 2395 ** extra argument must be a pointer to a constant UTF8 string which 2396 ** will become the new schema name in place of "main". ^SQLite does 2397 ** not make a copy of the new main schema name string, so the application 2398 ** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME 2399 ** is unchanged until after the database connection closes. 2400 ** </dd> 2401 ** 2402 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2403 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2404 ** <dd> Usually, when a database in [WAL mode] is closed or detached from a 2405 ** database handle, SQLite checks if if there are other connections to the 2406 ** same database, and if there are no other database connection (if the 2407 ** connection being closed is the last open connection to the database), 2408 ** then SQLite performs a [checkpoint] before closing the connection and 2409 ** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can 2410 ** be used to override that behavior. The first argument passed to this 2411 ** operation (the third parameter to [sqlite3_db_config()]) is an integer 2412 ** which is positive to disable checkpoints-on-close, or zero (the default) 2413 ** to enable them, and negative to leave the setting unchanged. 2414 ** The second argument (the fourth parameter) is a pointer to an integer 2415 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2416 ** have been disabled - 0 if they are not disabled, 1 if they are. 2417 ** </dd> 2418 ** 2419 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2420 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2421 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2422 ** a single SQL query statement will always use the same algorithm regardless 2423 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2424 ** that look at the values of bound parameters, which can make some queries 2425 ** slower. But the QPSG has the advantage of more predictable behavior. With 2426 ** the QPSG active, SQLite will always use the same query plan in the field as 2427 ** was used during testing in the lab. 2428 ** The first argument to this setting is an integer which is 0 to disable 2429 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2430 ** unchanged. The second parameter is a pointer to an integer into which 2431 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2432 ** following this call. 2433 ** </dd> 2434 ** 2435 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2436 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2437 ** include output for any operations performed by trigger programs. This 2438 ** option is used to set or clear (the default) a flag that governs this 2439 ** behavior. The first parameter passed to this operation is an integer - 2440 ** positive to enable output for trigger programs, or zero to disable it, 2441 ** or negative to leave the setting unchanged. 2442 ** The second parameter is a pointer to an integer into which is written 2443 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2444 ** it is not disabled, 1 if it is. 2445 ** </dd> 2446 ** 2447 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2448 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2449 ** [VACUUM] in order to reset a database back to an empty database 2450 ** with no schema and no content. The following process works even for 2451 ** a badly corrupted database file: 2452 ** <ol> 2453 ** <li> If the database connection is newly opened, make sure it has read the 2454 ** database schema by preparing then discarding some query against the 2455 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2456 ** errors. This step is only necessary if the application desires to keep 2457 ** the database in WAL mode after the reset if it was in WAL mode before 2458 ** the reset. 2459 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2460 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2461 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2462 ** </ol> 2463 ** Because resetting a database is destructive and irreversible, the 2464 ** process requires the use of this obscure API and multiple steps to 2465 ** help ensure that it does not happen by accident. Because this 2466 ** feature must be capable of resetting corrupt databases, and 2467 ** shutting down virtual tables may require access to that corrupt 2468 ** storage, the library must abandon any installed virtual tables 2469 ** without calling their xDestroy() methods. 2470 ** 2471 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2472 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2473 ** "defensive" flag for a database connection. When the defensive 2474 ** flag is enabled, language features that allow ordinary SQL to 2475 ** deliberately corrupt the database file are disabled. The disabled 2476 ** features include but are not limited to the following: 2477 ** <ul> 2478 ** <li> The [PRAGMA writable_schema=ON] statement. 2479 ** <li> The [PRAGMA journal_mode=OFF] statement. 2480 ** <li> The [PRAGMA schema_version=N] statement. 2481 ** <li> Writes to the [sqlite_dbpage] virtual table. 2482 ** <li> Direct writes to [shadow tables]. 2483 ** </ul> 2484 ** </dd> 2485 ** 2486 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2487 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2488 ** "writable_schema" flag. This has the same effect and is logically equivalent 2489 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2490 ** The first argument to this setting is an integer which is 0 to disable 2491 ** the writable_schema, positive to enable writable_schema, or negative to 2492 ** leave the setting unchanged. The second parameter is a pointer to an 2493 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2494 ** is enabled or disabled following this call. 2495 ** </dd> 2496 ** 2497 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2498 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2499 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2500 ** the legacy behavior of the [ALTER TABLE RENAME] command such that it 2501 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2502 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2503 ** additional information. This feature can also be turned on and off 2504 ** using the [PRAGMA legacy_alter_table] statement. 2505 ** </dd> 2506 ** 2507 ** [[SQLITE_DBCONFIG_DQS_DML]] 2508 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt> 2509 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2510 ** the legacy [double-quoted string literal] misfeature for DML statements 2511 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2512 ** default value of this setting is determined by the [-DSQLITE_DQS] 2513 ** compile-time option. 2514 ** </dd> 2515 ** 2516 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2517 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt> 2518 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2519 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2520 ** such as CREATE TABLE and CREATE INDEX. The 2521 ** default value of this setting is determined by the [-DSQLITE_DQS] 2522 ** compile-time option. 2523 ** </dd> 2524 ** 2525 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2526 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt> 2527 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2528 ** assume that database schemas are untainted by malicious content. 2529 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2530 ** takes additional defensive steps to protect the application from harm 2531 ** including: 2532 ** <ul> 2533 ** <li> Prohibit the use of SQL functions inside triggers, views, 2534 ** CHECK constraints, DEFAULT clauses, expression indexes, 2535 ** partial indexes, or generated columns 2536 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2537 ** <li> Prohibit the use of virtual tables inside of triggers or views 2538 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2539 ** </ul> 2540 ** This setting defaults to "on" for legacy compatibility, however 2541 ** all applications are advised to turn it off if possible. This setting 2542 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2543 ** </dd> 2544 ** 2545 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2546 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt> 2547 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2548 ** the legacy file format flag. When activated, this flag causes all newly 2549 ** created database files to have a schema format version number (the 4-byte 2550 ** integer found at offset 44 into the database header) of 1. This in turn 2551 ** means that the resulting database file will be readable and writable by 2552 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2553 ** newly created databases are generally not understandable by SQLite versions 2554 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2555 ** is now scarcely any need to generate database files that are compatible 2556 ** all the way back to version 3.0.0, and so this setting is of little 2557 ** practical use, but is provided so that SQLite can continue to claim the 2558 ** ability to generate new database files that are compatible with version 2559 ** 3.0.0. 2560 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2561 ** the [VACUUM] command will fail with an obscure error when attempting to 2562 ** process a table with generated columns and a descending index. This is 2563 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2564 ** either generated columns or descending indexes. 2565 ** </dd> 2566 ** 2567 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]] 2568 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt> 2569 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in 2570 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears 2571 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2() 2572 ** statistics. For statistics to be collected, the flag must be set on 2573 ** the database handle both when the SQL statement is prepared and when it 2574 ** is stepped. The flag is set (collection of statistics is enabled) 2575 ** by default. <p>This option takes two arguments: an integer and a pointer to 2576 ** an integer. The first argument is 1, 0, or -1 to enable, disable, or 2577 ** leave unchanged the statement scanstatus option. If the second argument 2578 ** is not NULL, then the value of the statement scanstatus setting after 2579 ** processing the first argument is written into the integer that the second 2580 ** argument points to. 2581 ** </dd> 2582 ** 2583 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]] 2584 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt> 2585 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order 2586 ** in which tables and indexes are scanned so that the scans start at the end 2587 ** and work toward the beginning rather than starting at the beginning and 2588 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the 2589 ** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes 2590 ** two arguments which are an integer and a pointer to an integer. The first 2591 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the 2592 ** reverse scan order flag, respectively. If the second argument is not NULL, 2593 ** then 0 or 1 is written into the integer that the second argument points to 2594 ** depending on if the reverse scan order flag is set after processing the 2595 ** first argument. 2596 ** </dd> 2597 ** 2598 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]] 2599 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt> 2600 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables 2601 ** the ability of the [ATTACH DATABASE] SQL command to create a new database 2602 ** file if the database filed named in the ATTACH command does not already 2603 ** exist. This ability of ATTACH to create a new database is enabled by 2604 ** default. Applications can disable or reenable the ability for ATTACH to 2605 ** create new database files using this DBCONFIG option.<p> 2606 ** This option takes two arguments which are an integer and a pointer 2607 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or 2608 ** leave unchanged the attach-create flag, respectively. If the second 2609 ** argument is not NULL, then 0 or 1 is written into the integer that the 2610 ** second argument points to depending on if the attach-create flag is set 2611 ** after processing the first argument. 2612 ** </dd> 2613 ** 2614 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]] 2615 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt> 2616 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the 2617 ** ability of the [ATTACH DATABASE] SQL command to open a database for writing. 2618 ** This capability is enabled by default. Applications can disable or 2619 ** reenable this capability using the current DBCONFIG option. If 2620 ** this capability is disabled, the [ATTACH] command will still work, 2621 ** but the database will be opened read-only. If this option is disabled, 2622 ** then the ability to create a new database using [ATTACH] is also disabled, 2623 ** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE] 2624 ** option.<p> 2625 ** This option takes two arguments which are an integer and a pointer 2626 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or 2627 ** leave unchanged the ability to ATTACH another database for writing, 2628 ** respectively. If the second argument is not NULL, then 0 or 1 is written 2629 ** into the integer to which the second argument points, depending on whether 2630 ** the ability to ATTACH a read/write database is enabled or disabled 2631 ** after processing the first argument. 2632 ** </dd> 2633 ** 2634 ** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]] 2635 ** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt> 2636 ** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the 2637 ** ability to include comments in SQL text. Comments are enabled by default. 2638 ** An application can disable or reenable comments in SQL text using this 2639 ** DBCONFIG option.<p> 2640 ** This option takes two arguments which are an integer and a pointer 2641 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or 2642 ** leave unchanged the ability to use comments in SQL text, 2643 ** respectively. If the second argument is not NULL, then 0 or 1 is written 2644 ** into the integer that the second argument points to depending on if 2645 ** comments are allowed in SQL text after processing the first argument. 2646 ** </dd> 2647 ** 2648 ** </dl> 2649 ** 2650 ** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3> 2651 ** 2652 ** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the 2653 ** overall call to [sqlite3_db_config()] has a total of four parameters. 2654 ** The first argument (the third parameter to sqlite3_db_config()) is an integer. 2655 ** The second argument is a pointer to an integer. If the first argument is 1, 2656 ** then the option becomes enabled. If the first integer argument is 0, then the 2657 ** option is disabled. If the first argument is -1, then the option setting 2658 ** is unchanged. The second argument, the pointer to an integer, may be NULL. 2659 ** If the second argument is not NULL, then a value of 0 or 1 is written into 2660 ** the integer to which the second argument points, depending on whether the 2661 ** setting is disabled or enabled after applying any changes specified by 2662 ** the first argument. 2663 ** 2664 ** <p>While most SQLITE_DBCONFIG options use the argument format 2665 ** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME] 2666 ** and [SQLITE_DBCONFIG_LOOKASIDE] options are different. See the 2667 ** documentation of those exceptional options for details. 2668 */ 2669 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2670 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2671 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2672 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2673 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2674 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2675 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2676 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2677 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2678 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2679 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2680 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2681 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2682 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2683 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2684 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2685 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2686 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2687 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */ 2688 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */ 2689 #define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */ 2690 #define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */ 2691 #define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */ 2692 #define SQLITE_DBCONFIG_MAX 1022 /* Largest DBCONFIG */ 2693 2694 /* 2695 ** CAPI3REF: Enable Or Disable Extended Result Codes 2696 ** METHOD: sqlite3 2697 ** 2698 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2699 ** [extended result codes] feature of SQLite. ^The extended result 2700 ** codes are disabled by default for historical compatibility. 2701 */ 2702 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2703 2704 /* 2705 ** CAPI3REF: Last Insert Rowid 2706 ** METHOD: sqlite3 2707 ** 2708 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2709 ** has a unique 64-bit signed 2710 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2711 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2712 ** names are not also used by explicitly declared columns. ^If 2713 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2714 ** is another alias for the rowid. 2715 ** 2716 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2717 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2718 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2719 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2720 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2721 ** zero. 2722 ** 2723 ** As well as being set automatically as rows are inserted into database 2724 ** tables, the value returned by this function may be set explicitly by 2725 ** [sqlite3_set_last_insert_rowid()] 2726 ** 2727 ** Some virtual table implementations may INSERT rows into rowid tables as 2728 ** part of committing a transaction (e.g. to flush data accumulated in memory 2729 ** to disk). In this case subsequent calls to this function return the rowid 2730 ** associated with these internal INSERT operations, which leads to 2731 ** unintuitive results. Virtual table implementations that do write to rowid 2732 ** tables in this way can avoid this problem by restoring the original 2733 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2734 ** control to the user. 2735 ** 2736 ** ^(If an [INSERT] occurs within a trigger then this routine will 2737 ** return the [rowid] of the inserted row as long as the trigger is 2738 ** running. Once the trigger program ends, the value returned 2739 ** by this routine reverts to what it was before the trigger was fired.)^ 2740 ** 2741 ** ^An [INSERT] that fails due to a constraint violation is not a 2742 ** successful [INSERT] and does not change the value returned by this 2743 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2744 ** and INSERT OR ABORT make no changes to the return value of this 2745 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2746 ** encounters a constraint violation, it does not fail. The 2747 ** INSERT continues to completion after deleting rows that caused 2748 ** the constraint problem so INSERT OR REPLACE will always change 2749 ** the return value of this interface.)^ 2750 ** 2751 ** ^For the purposes of this routine, an [INSERT] is considered to 2752 ** be successful even if it is subsequently rolled back. 2753 ** 2754 ** This function is accessible to SQL statements via the 2755 ** [last_insert_rowid() SQL function]. 2756 ** 2757 ** If a separate thread performs a new [INSERT] on the same 2758 ** database connection while the [sqlite3_last_insert_rowid()] 2759 ** function is running and thus changes the last insert [rowid], 2760 ** then the value returned by [sqlite3_last_insert_rowid()] is 2761 ** unpredictable and might not equal either the old or the new 2762 ** last insert [rowid]. 2763 */ 2764 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2765 2766 /* 2767 ** CAPI3REF: Set the Last Insert Rowid value. 2768 ** METHOD: sqlite3 2769 ** 2770 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2771 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2772 ** without inserting a row into the database. 2773 */ 2774 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2775 2776 /* 2777 ** CAPI3REF: Count The Number Of Rows Modified 2778 ** METHOD: sqlite3 2779 ** 2780 ** ^These functions return the number of rows modified, inserted or 2781 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2782 ** statement on the database connection specified by the only parameter. 2783 ** The two functions are identical except for the type of the return value 2784 ** and that if the number of rows modified by the most recent INSERT, UPDATE, 2785 ** or DELETE is greater than the maximum value supported by type "int", then 2786 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2787 ** type of SQL statement does not modify the value returned by these functions. 2788 ** For the purposes of this interface, a CREATE TABLE AS SELECT statement 2789 ** does not count as an INSERT, UPDATE or DELETE statement and hence the rows 2790 ** added to the new table by the CREATE TABLE AS SELECT statement are not 2791 ** counted. 2792 ** 2793 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2794 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2795 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2796 ** 2797 ** Changes to a view that are intercepted by 2798 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2799 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2800 ** DELETE statement run on a view is always zero. Only changes made to real 2801 ** tables are counted. 2802 ** 2803 ** Things are more complicated if the sqlite3_changes() function is 2804 ** executed while a trigger program is running. This may happen if the 2805 ** program uses the [changes() SQL function], or if some other callback 2806 ** function invokes sqlite3_changes() directly. Essentially: 2807 ** 2808 ** <ul> 2809 ** <li> ^(Before entering a trigger program the value returned by 2810 ** sqlite3_changes() function is saved. After the trigger program 2811 ** has finished, the original value is restored.)^ 2812 ** 2813 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2814 ** statement sets the value returned by sqlite3_changes() 2815 ** upon completion as normal. Of course, this value will not include 2816 ** any changes performed by sub-triggers, as the sqlite3_changes() 2817 ** value will be saved and restored after each sub-trigger has run.)^ 2818 ** </ul> 2819 ** 2820 ** ^This means that if the changes() SQL function (or similar) is used 2821 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2822 ** returns the value as set when the calling statement began executing. 2823 ** ^If it is used by the second or subsequent such statement within a trigger 2824 ** program, the value returned reflects the number of rows modified by the 2825 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2826 ** 2827 ** If a separate thread makes changes on the same database connection 2828 ** while [sqlite3_changes()] is running then the value returned 2829 ** is unpredictable and not meaningful. 2830 ** 2831 ** See also: 2832 ** <ul> 2833 ** <li> the [sqlite3_total_changes()] interface 2834 ** <li> the [count_changes pragma] 2835 ** <li> the [changes() SQL function] 2836 ** <li> the [data_version pragma] 2837 ** </ul> 2838 */ 2839 SQLITE_API int sqlite3_changes(sqlite3*); 2840 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2841 2842 /* 2843 ** CAPI3REF: Total Number Of Rows Modified 2844 ** METHOD: sqlite3 2845 ** 2846 ** ^These functions return the total number of rows inserted, modified or 2847 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2848 ** since the database connection was opened, including those executed as 2849 ** part of trigger programs. The two functions are identical except for the 2850 ** type of the return value and that if the number of rows modified by the 2851 ** connection exceeds the maximum value supported by type "int", then 2852 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2853 ** any other type of SQL statement does not affect the value returned by 2854 ** sqlite3_total_changes(). 2855 ** 2856 ** ^Changes made as part of [foreign key actions] are included in the 2857 ** count, but those made as part of REPLACE constraint resolution are 2858 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2859 ** are not counted. 2860 ** 2861 ** The [sqlite3_total_changes(D)] interface only reports the number 2862 ** of rows that changed due to SQL statement run against database 2863 ** connection D. Any changes by other database connections are ignored. 2864 ** To detect changes against a database file from other database 2865 ** connections use the [PRAGMA data_version] command or the 2866 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2867 ** 2868 ** If a separate thread makes changes on the same database connection 2869 ** while [sqlite3_total_changes()] is running then the value 2870 ** returned is unpredictable and not meaningful. 2871 ** 2872 ** See also: 2873 ** <ul> 2874 ** <li> the [sqlite3_changes()] interface 2875 ** <li> the [count_changes pragma] 2876 ** <li> the [changes() SQL function] 2877 ** <li> the [data_version pragma] 2878 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2879 ** </ul> 2880 */ 2881 SQLITE_API int sqlite3_total_changes(sqlite3*); 2882 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2883 2884 /* 2885 ** CAPI3REF: Interrupt A Long-Running Query 2886 ** METHOD: sqlite3 2887 ** 2888 ** ^This function causes any pending database operation to abort and 2889 ** return at its earliest opportunity. This routine is typically 2890 ** called in response to a user action such as pressing "Cancel" 2891 ** or Ctrl-C where the user wants a long query operation to halt 2892 ** immediately. 2893 ** 2894 ** ^It is safe to call this routine from a thread different from the 2895 ** thread that is currently running the database operation. But it 2896 ** is not safe to call this routine with a [database connection] that 2897 ** is closed or might close before sqlite3_interrupt() returns. 2898 ** 2899 ** ^If an SQL operation is very nearly finished at the time when 2900 ** sqlite3_interrupt() is called, then it might not have an opportunity 2901 ** to be interrupted and might continue to completion. 2902 ** 2903 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2904 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2905 ** that is inside an explicit transaction, then the entire transaction 2906 ** will be rolled back automatically. 2907 ** 2908 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2909 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2910 ** that are started after the sqlite3_interrupt() call and before the 2911 ** running statement count reaches zero are interrupted as if they had been 2912 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2913 ** that are started after the running statement count reaches zero are 2914 ** not effected by the sqlite3_interrupt(). 2915 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2916 ** SQL statements is a no-op and has no effect on SQL statements 2917 ** that are started after the sqlite3_interrupt() call returns. 2918 ** 2919 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether 2920 ** or not an interrupt is currently in effect for [database connection] D. 2921 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise. 2922 */ 2923 SQLITE_API void sqlite3_interrupt(sqlite3*); 2924 SQLITE_API int sqlite3_is_interrupted(sqlite3*); 2925 2926 /* 2927 ** CAPI3REF: Determine If An SQL Statement Is Complete 2928 ** 2929 ** These routines are useful during command-line input to determine if the 2930 ** currently entered text seems to form a complete SQL statement or 2931 ** if additional input is needed before sending the text into 2932 ** SQLite for parsing. ^These routines return 1 if the input string 2933 ** appears to be a complete SQL statement. ^A statement is judged to be 2934 ** complete if it ends with a semicolon token and is not a prefix of a 2935 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2936 ** string literals or quoted identifier names or comments are not 2937 ** independent tokens (they are part of the token in which they are 2938 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2939 ** and comments that follow the final semicolon are ignored. 2940 ** 2941 ** ^These routines return 0 if the statement is incomplete. ^If a 2942 ** memory allocation fails, then SQLITE_NOMEM is returned. 2943 ** 2944 ** ^These routines do not parse the SQL statements and thus 2945 ** will not detect syntactically incorrect SQL. 2946 ** 2947 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2948 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2949 ** automatically by sqlite3_complete16(). If that initialization fails, 2950 ** then the return value from sqlite3_complete16() will be non-zero 2951 ** regardless of whether or not the input SQL is complete.)^ 2952 ** 2953 ** The input to [sqlite3_complete()] must be a zero-terminated 2954 ** UTF-8 string. 2955 ** 2956 ** The input to [sqlite3_complete16()] must be a zero-terminated 2957 ** UTF-16 string in native byte order. 2958 */ 2959 SQLITE_API int sqlite3_complete(const char *sql); 2960 SQLITE_API int sqlite3_complete16(const void *sql); 2961 2962 /* 2963 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2964 ** KEYWORDS: {busy-handler callback} {busy handler} 2965 ** METHOD: sqlite3 2966 ** 2967 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2968 ** that might be invoked with argument P whenever 2969 ** an attempt is made to access a database table associated with 2970 ** [database connection] D when another thread 2971 ** or process has the table locked. 2972 ** The sqlite3_busy_handler() interface is used to implement 2973 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2974 ** 2975 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2976 ** is returned immediately upon encountering the lock. ^If the busy callback 2977 ** is not NULL, then the callback might be invoked with two arguments. 2978 ** 2979 ** ^The first argument to the busy handler is a copy of the void* pointer which 2980 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2981 ** the busy handler callback is the number of times that the busy handler has 2982 ** been invoked previously for the same locking event. ^If the 2983 ** busy callback returns 0, then no additional attempts are made to 2984 ** access the database and [SQLITE_BUSY] is returned 2985 ** to the application. 2986 ** ^If the callback returns non-zero, then another attempt 2987 ** is made to access the database and the cycle repeats. 2988 ** 2989 ** The presence of a busy handler does not guarantee that it will be invoked 2990 ** when there is lock contention. ^If SQLite determines that invoking the busy 2991 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2992 ** to the application instead of invoking the 2993 ** busy handler. 2994 ** Consider a scenario where one process is holding a read lock that 2995 ** it is trying to promote to a reserved lock and 2996 ** a second process is holding a reserved lock that it is trying 2997 ** to promote to an exclusive lock. The first process cannot proceed 2998 ** because it is blocked by the second and the second process cannot 2999 ** proceed because it is blocked by the first. If both processes 3000 ** invoke the busy handlers, neither will make any progress. Therefore, 3001 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 3002 ** will induce the first process to release its read lock and allow 3003 ** the second process to proceed. 3004 ** 3005 ** ^The default busy callback is NULL. 3006 ** 3007 ** ^(There can only be a single busy handler defined for each 3008 ** [database connection]. Setting a new busy handler clears any 3009 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 3010 ** or evaluating [PRAGMA busy_timeout=N] will change the 3011 ** busy handler and thus clear any previously set busy handler. 3012 ** 3013 ** The busy callback should not take any actions which modify the 3014 ** database connection that invoked the busy handler. In other words, 3015 ** the busy handler is not reentrant. Any such actions 3016 ** result in undefined behavior. 3017 ** 3018 ** A busy handler must not close the database connection 3019 ** or [prepared statement] that invoked the busy handler. 3020 */ 3021 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 3022 3023 /* 3024 ** CAPI3REF: Set A Busy Timeout 3025 ** METHOD: sqlite3 3026 ** 3027 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 3028 ** for a specified amount of time when a table is locked. ^The handler 3029 ** will sleep multiple times until at least "ms" milliseconds of sleeping 3030 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 3031 ** the handler returns 0 which causes [sqlite3_step()] to return 3032 ** [SQLITE_BUSY]. 3033 ** 3034 ** ^Calling this routine with an argument less than or equal to zero 3035 ** turns off all busy handlers. 3036 ** 3037 ** ^(There can only be a single busy handler for a particular 3038 ** [database connection] at any given moment. If another busy handler 3039 ** was defined (using [sqlite3_busy_handler()]) prior to calling 3040 ** this routine, that other busy handler is cleared.)^ 3041 ** 3042 ** See also: [PRAGMA busy_timeout] 3043 */ 3044 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 3045 3046 /* 3047 ** CAPI3REF: Set the Setlk Timeout 3048 ** METHOD: sqlite3 3049 ** 3050 ** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If 3051 ** the VFS supports blocking locks, it sets the timeout in ms used by 3052 ** eligible locks taken on wal mode databases by the specified database 3053 ** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does 3054 ** not support blocking locks, this function is a no-op. 3055 ** 3056 ** Passing 0 to this function disables blocking locks altogether. Passing 3057 ** -1 to this function requests that the VFS blocks for a long time - 3058 ** indefinitely if possible. The results of passing any other negative value 3059 ** are undefined. 3060 ** 3061 ** Internally, each SQLite database handle stores two timeout values - the 3062 ** busy-timeout (used for rollback mode databases, or if the VFS does not 3063 ** support blocking locks) and the setlk-timeout (used for blocking locks 3064 ** on wal-mode databases). The sqlite3_busy_timeout() method sets both 3065 ** values, this function sets only the setlk-timeout value. Therefore, 3066 ** to configure separate busy-timeout and setlk-timeout values for a single 3067 ** database handle, call sqlite3_busy_timeout() followed by this function. 3068 ** 3069 ** Whenever the number of connections to a wal mode database falls from 3070 ** 1 to 0, the last connection takes an exclusive lock on the database, 3071 ** then checkpoints and deletes the wal file. While it is doing this, any 3072 ** new connection that tries to read from the database fails with an 3073 ** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is 3074 ** passed to this API, the new connection blocks until the exclusive lock 3075 ** has been released. 3076 */ 3077 SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags); 3078 3079 /* 3080 ** CAPI3REF: Flags for sqlite3_setlk_timeout() 3081 */ 3082 #define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01 3083 3084 /* 3085 ** CAPI3REF: Convenience Routines For Running Queries 3086 ** METHOD: sqlite3 3087 ** 3088 ** This is a legacy interface that is preserved for backwards compatibility. 3089 ** Use of this interface is not recommended. 3090 ** 3091 ** Definition: A <b>result table</b> is a memory data structure created by the 3092 ** [sqlite3_get_table()] interface. A result table records the 3093 ** complete query results from one or more queries. 3094 ** 3095 ** The table conceptually has a number of rows and columns. But 3096 ** these numbers are not part of the result table itself. These 3097 ** numbers are obtained separately. Let N be the number of rows 3098 ** and M be the number of columns. 3099 ** 3100 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 3101 ** There are (N+1)*M elements in the array. The first M pointers point 3102 ** to zero-terminated strings that contain the names of the columns. 3103 ** The remaining entries all point to query results. NULL values result 3104 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 3105 ** string representation as returned by [sqlite3_column_text()]. 3106 ** 3107 ** A result table might consist of one or more memory allocations. 3108 ** It is not safe to pass a result table directly to [sqlite3_free()]. 3109 ** A result table should be deallocated using [sqlite3_free_table()]. 3110 ** 3111 ** ^(As an example of the result table format, suppose a query result 3112 ** is as follows: 3113 ** 3114 ** <blockquote><pre> 3115 ** Name | Age 3116 ** ----------------------- 3117 ** Alice | 43 3118 ** Bob | 28 3119 ** Cindy | 21 3120 ** </pre></blockquote> 3121 ** 3122 ** There are two columns (M==2) and three rows (N==3). Thus the 3123 ** result table has 8 entries. Suppose the result table is stored 3124 ** in an array named azResult. Then azResult holds this content: 3125 ** 3126 ** <blockquote><pre> 3127 ** azResult[0] = "Name"; 3128 ** azResult[1] = "Age"; 3129 ** azResult[2] = "Alice"; 3130 ** azResult[3] = "43"; 3131 ** azResult[4] = "Bob"; 3132 ** azResult[5] = "28"; 3133 ** azResult[6] = "Cindy"; 3134 ** azResult[7] = "21"; 3135 ** </pre></blockquote>)^ 3136 ** 3137 ** ^The sqlite3_get_table() function evaluates one or more 3138 ** semicolon-separated SQL statements in the zero-terminated UTF-8 3139 ** string of its 2nd parameter and returns a result table to the 3140 ** pointer given in its 3rd parameter. 3141 ** 3142 ** After the application has finished with the result from sqlite3_get_table(), 3143 ** it must pass the result table pointer to sqlite3_free_table() in order to 3144 ** release the memory that was malloced. Because of the way the 3145 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 3146 ** function must not try to call [sqlite3_free()] directly. Only 3147 ** [sqlite3_free_table()] is able to release the memory properly and safely. 3148 ** 3149 ** The sqlite3_get_table() interface is implemented as a wrapper around 3150 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 3151 ** to any internal data structures of SQLite. It uses only the public 3152 ** interface defined here. As a consequence, errors that occur in the 3153 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 3154 ** reflected in subsequent calls to [sqlite3_errcode()] or 3155 ** [sqlite3_errmsg()]. 3156 */ 3157 SQLITE_API int sqlite3_get_table( 3158 sqlite3 *db, /* An open database */ 3159 const char *zSql, /* SQL to be evaluated */ 3160 char ***pazResult, /* Results of the query */ 3161 int *pnRow, /* Number of result rows written here */ 3162 int *pnColumn, /* Number of result columns written here */ 3163 char **pzErrmsg /* Error msg written here */ 3164 ); 3165 SQLITE_API void sqlite3_free_table(char **result); 3166 3167 /* 3168 ** CAPI3REF: Formatted String Printing Functions 3169 ** 3170 ** These routines are work-alikes of the "printf()" family of functions 3171 ** from the standard C library. 3172 ** These routines understand most of the common formatting options from 3173 ** the standard library printf() 3174 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 3175 ** See the [built-in printf()] documentation for details. 3176 ** 3177 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 3178 ** results into memory obtained from [sqlite3_malloc64()]. 3179 ** The strings returned by these two routines should be 3180 ** released by [sqlite3_free()]. ^Both routines return a 3181 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 3182 ** memory to hold the resulting string. 3183 ** 3184 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 3185 ** the standard C library. The result is written into the 3186 ** buffer supplied as the second parameter whose size is given by 3187 ** the first parameter. Note that the order of the 3188 ** first two parameters is reversed from snprintf().)^ This is an 3189 ** historical accident that cannot be fixed without breaking 3190 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 3191 ** returns a pointer to its buffer instead of the number of 3192 ** characters actually written into the buffer.)^ We admit that 3193 ** the number of characters written would be a more useful return 3194 ** value but we cannot change the implementation of sqlite3_snprintf() 3195 ** now without breaking compatibility. 3196 ** 3197 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 3198 ** guarantees that the buffer is always zero-terminated. ^The first 3199 ** parameter "n" is the total size of the buffer, including space for 3200 ** the zero terminator. So the longest string that can be completely 3201 ** written will be n-1 characters. 3202 ** 3203 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 3204 ** 3205 ** See also: [built-in printf()], [printf() SQL function] 3206 */ 3207 SQLITE_API char *sqlite3_mprintf(const char*,...); 3208 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 3209 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 3210 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 3211 3212 /* 3213 ** CAPI3REF: Memory Allocation Subsystem 3214 ** 3215 ** The SQLite core uses these three routines for all of its own 3216 ** internal memory allocation needs. "Core" in the previous sentence 3217 ** does not include operating-system specific [VFS] implementation. The 3218 ** Windows VFS uses native malloc() and free() for some operations. 3219 ** 3220 ** ^The sqlite3_malloc() routine returns a pointer to a block 3221 ** of memory at least N bytes in length, where N is the parameter. 3222 ** ^If sqlite3_malloc() is unable to obtain sufficient free 3223 ** memory, it returns a NULL pointer. ^If the parameter N to 3224 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 3225 ** a NULL pointer. 3226 ** 3227 ** ^The sqlite3_malloc64(N) routine works just like 3228 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 3229 ** of a signed 32-bit integer. 3230 ** 3231 ** ^Calling sqlite3_free() with a pointer previously returned 3232 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 3233 ** that it might be reused. ^The sqlite3_free() routine is 3234 ** a no-op if it is called with a NULL pointer. Passing a NULL pointer 3235 ** to sqlite3_free() is harmless. After being freed, memory 3236 ** should neither be read nor written. Even reading previously freed 3237 ** memory might result in a segmentation fault or other severe error. 3238 ** Memory corruption, a segmentation fault, or other severe error 3239 ** might result if sqlite3_free() is called with a non-NULL pointer that 3240 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 3241 ** 3242 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 3243 ** prior memory allocation X to be at least N bytes. 3244 ** ^If the X parameter to sqlite3_realloc(X,N) 3245 ** is a NULL pointer then its behavior is identical to calling 3246 ** sqlite3_malloc(N). 3247 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 3248 ** negative then the behavior is exactly the same as calling 3249 ** sqlite3_free(X). 3250 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 3251 ** of at least N bytes in size or NULL if insufficient memory is available. 3252 ** ^If M is the size of the prior allocation, then min(N,M) bytes of the 3253 ** prior allocation are copied into the beginning of the buffer returned 3254 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 3255 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 3256 ** prior allocation is not freed. 3257 ** 3258 ** ^The sqlite3_realloc64(X,N) interface works the same as 3259 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 3260 ** of a 32-bit signed integer. 3261 ** 3262 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 3263 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 3264 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 3265 ** ^The value returned by sqlite3_msize(X) might be larger than the number 3266 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 3267 ** sqlite3_msize(X) returns zero. If X points to something that is not 3268 ** the beginning of memory allocation, or if it points to a formerly 3269 ** valid memory allocation that has now been freed, then the behavior 3270 ** of sqlite3_msize(X) is undefined and possibly harmful. 3271 ** 3272 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 3273 ** sqlite3_malloc64(), and sqlite3_realloc64() 3274 ** is always aligned to at least an 8 byte boundary, or to a 3275 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 3276 ** option is used. 3277 ** 3278 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 3279 ** must be either NULL or else pointers obtained from a prior 3280 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 3281 ** not yet been released. 3282 ** 3283 ** The application must not read or write any part of 3284 ** a block of memory after it has been released using 3285 ** [sqlite3_free()] or [sqlite3_realloc()]. 3286 */ 3287 SQLITE_API void *sqlite3_malloc(int); 3288 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 3289 SQLITE_API void *sqlite3_realloc(void*, int); 3290 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3291 SQLITE_API void sqlite3_free(void*); 3292 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3293 3294 /* 3295 ** CAPI3REF: Memory Allocator Statistics 3296 ** 3297 ** SQLite provides these two interfaces for reporting on the status 3298 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3299 ** routines, which form the built-in memory allocation subsystem. 3300 ** 3301 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 3302 ** of memory currently outstanding (malloced but not freed). 3303 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 3304 ** value of [sqlite3_memory_used()] since the high-water mark 3305 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 3306 ** [sqlite3_memory_highwater()] include any overhead 3307 ** added by SQLite in its implementation of [sqlite3_malloc()], 3308 ** but not overhead added by any underlying system library 3309 ** routines that [sqlite3_malloc()] may call. 3310 ** 3311 ** ^The memory high-water mark is reset to the current value of 3312 ** [sqlite3_memory_used()] if and only if the parameter to 3313 ** [sqlite3_memory_highwater()] is true. ^The value returned 3314 ** by [sqlite3_memory_highwater(1)] is the high-water mark 3315 ** prior to the reset. 3316 */ 3317 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3318 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3319 3320 /* 3321 ** CAPI3REF: Pseudo-Random Number Generator 3322 ** 3323 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3324 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3325 ** already uses the largest possible [ROWID]. The PRNG is also used for 3326 ** the built-in random() and randomblob() SQL functions. This interface allows 3327 ** applications to access the same PRNG for other purposes. 3328 ** 3329 ** ^A call to this routine stores N bytes of randomness into buffer P. 3330 ** ^The P parameter can be a NULL pointer. 3331 ** 3332 ** ^If this routine has not been previously called or if the previous 3333 ** call had N less than one or a NULL pointer for P, then the PRNG is 3334 ** seeded using randomness obtained from the xRandomness method of 3335 ** the default [sqlite3_vfs] object. 3336 ** ^If the previous call to this routine had an N of 1 or more and a 3337 ** non-NULL P then the pseudo-randomness is generated 3338 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3339 ** method. 3340 */ 3341 SQLITE_API void sqlite3_randomness(int N, void *P); 3342 3343 /* 3344 ** CAPI3REF: Compile-Time Authorization Callbacks 3345 ** METHOD: sqlite3 3346 ** KEYWORDS: {authorizer callback} 3347 ** 3348 ** ^This routine registers an authorizer callback with a particular 3349 ** [database connection], supplied in the first argument. 3350 ** ^The authorizer callback is invoked as SQL statements are being compiled 3351 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3352 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3353 ** and [sqlite3_prepare16_v3()]. ^At various 3354 ** points during the compilation process, as logic is being created 3355 ** to perform various actions, the authorizer callback is invoked to 3356 ** see if those actions are allowed. ^The authorizer callback should 3357 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3358 ** specific action but allow the SQL statement to continue to be 3359 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3360 ** rejected with an error. ^If the authorizer callback returns 3361 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3362 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3363 ** the authorizer will fail with an error message. 3364 ** 3365 ** When the callback returns [SQLITE_OK], that means the operation 3366 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3367 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3368 ** authorizer will fail with an error message explaining that 3369 ** access is denied. 3370 ** 3371 ** ^The first parameter to the authorizer callback is a copy of the third 3372 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3373 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3374 ** the particular action to be authorized. ^The third through sixth parameters 3375 ** to the callback are either NULL pointers or zero-terminated strings 3376 ** that contain additional details about the action to be authorized. 3377 ** Applications must always be prepared to encounter a NULL pointer in any 3378 ** of the third through the sixth parameters of the authorization callback. 3379 ** 3380 ** ^If the action code is [SQLITE_READ] 3381 ** and the callback returns [SQLITE_IGNORE] then the 3382 ** [prepared statement] statement is constructed to substitute 3383 ** a NULL value in place of the table column that would have 3384 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3385 ** return can be used to deny an untrusted user access to individual 3386 ** columns of a table. 3387 ** ^When a table is referenced by a [SELECT] but no column values are 3388 ** extracted from that table (for example in a query like 3389 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3390 ** is invoked once for that table with a column name that is an empty string. 3391 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3392 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3393 ** [truncate optimization] is disabled and all rows are deleted individually. 3394 ** 3395 ** An authorizer is used when [sqlite3_prepare | preparing] 3396 ** SQL statements from an untrusted source, to ensure that the SQL statements 3397 ** do not try to access data they are not allowed to see, or that they do not 3398 ** try to execute malicious statements that damage the database. For 3399 ** example, an application may allow a user to enter arbitrary 3400 ** SQL queries for evaluation by a database. But the application does 3401 ** not want the user to be able to make arbitrary changes to the 3402 ** database. An authorizer could then be put in place while the 3403 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3404 ** disallows everything except [SELECT] statements. 3405 ** 3406 ** Applications that need to process SQL from untrusted sources 3407 ** might also consider lowering resource limits using [sqlite3_limit()] 3408 ** and limiting database size using the [max_page_count] [PRAGMA] 3409 ** in addition to using an authorizer. 3410 ** 3411 ** ^(Only a single authorizer can be in place on a database connection 3412 ** at a time. Each call to sqlite3_set_authorizer overrides the 3413 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3414 ** The authorizer is disabled by default. 3415 ** 3416 ** The authorizer callback must not do anything that will modify 3417 ** the database connection that invoked the authorizer callback. 3418 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3419 ** database connections for the meaning of "modify" in this paragraph. 3420 ** 3421 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3422 ** statement might be re-prepared during [sqlite3_step()] due to a 3423 ** schema change. Hence, the application should ensure that the 3424 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3425 ** 3426 ** ^Note that the authorizer callback is invoked only during 3427 ** [sqlite3_prepare()] or its variants. Authorization is not 3428 ** performed during statement evaluation in [sqlite3_step()], unless 3429 ** as stated in the previous paragraph, sqlite3_step() invokes 3430 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3431 */ 3432 SQLITE_API int sqlite3_set_authorizer( 3433 sqlite3*, 3434 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3435 void *pUserData 3436 ); 3437 3438 /* 3439 ** CAPI3REF: Authorizer Return Codes 3440 ** 3441 ** The [sqlite3_set_authorizer | authorizer callback function] must 3442 ** return either [SQLITE_OK] or one of these two constants in order 3443 ** to signal SQLite whether or not the action is permitted. See the 3444 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3445 ** information. 3446 ** 3447 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3448 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3449 */ 3450 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3451 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3452 3453 /* 3454 ** CAPI3REF: Authorizer Action Codes 3455 ** 3456 ** The [sqlite3_set_authorizer()] interface registers a callback function 3457 ** that is invoked to authorize certain SQL statement actions. The 3458 ** second parameter to the callback is an integer code that specifies 3459 ** what action is being authorized. These are the integer action codes that 3460 ** the authorizer callback may be passed. 3461 ** 3462 ** These action code values signify what kind of operation is to be 3463 ** authorized. The 3rd and 4th parameters to the authorization 3464 ** callback function will be parameters or NULL depending on which of these 3465 ** codes is used as the second parameter. ^(The 5th parameter to the 3466 ** authorizer callback is the name of the database ("main", "temp", 3467 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3468 ** is the name of the inner-most trigger or view that is responsible for 3469 ** the access attempt or NULL if this access attempt is directly from 3470 ** top-level SQL code. 3471 */ 3472 /******************************************* 3rd ************ 4th ***********/ 3473 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3474 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3475 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3476 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3477 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3478 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3479 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3480 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3481 #define SQLITE_DELETE 9 /* Table Name NULL */ 3482 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3483 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3484 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3485 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3486 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3487 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3488 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3489 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3490 #define SQLITE_INSERT 18 /* Table Name NULL */ 3491 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3492 #define SQLITE_READ 20 /* Table Name Column Name */ 3493 #define SQLITE_SELECT 21 /* NULL NULL */ 3494 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3495 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3496 #define SQLITE_ATTACH 24 /* Filename NULL */ 3497 #define SQLITE_DETACH 25 /* Database Name NULL */ 3498 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3499 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3500 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3501 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3502 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3503 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3504 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3505 #define SQLITE_COPY 0 /* No longer used */ 3506 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3507 3508 /* 3509 ** CAPI3REF: Deprecated Tracing And Profiling Functions 3510 ** DEPRECATED 3511 ** 3512 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3513 ** instead of the routines described here. 3514 ** 3515 ** These routines register callback functions that can be used for 3516 ** tracing and profiling the execution of SQL statements. 3517 ** 3518 ** ^The callback function registered by sqlite3_trace() is invoked at 3519 ** various times when an SQL statement is being run by [sqlite3_step()]. 3520 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3521 ** SQL statement text as the statement first begins executing. 3522 ** ^(Additional sqlite3_trace() callbacks might occur 3523 ** as each triggered subprogram is entered. The callbacks for triggers 3524 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3525 ** 3526 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3527 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3528 ** 3529 ** ^The callback function registered by sqlite3_profile() is invoked 3530 ** as each SQL statement finishes. ^The profile callback contains 3531 ** the original statement text and an estimate of wall-clock time 3532 ** of how long that statement took to run. ^The profile callback 3533 ** time is in units of nanoseconds, however the current implementation 3534 ** is only capable of millisecond resolution so the six least significant 3535 ** digits in the time are meaningless. Future versions of SQLite 3536 ** might provide greater resolution on the profiler callback. Invoking 3537 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3538 ** profile callback. 3539 */ 3540 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3541 void(*xTrace)(void*,const char*), void*); 3542 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3543 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3544 3545 /* 3546 ** CAPI3REF: SQL Trace Event Codes 3547 ** KEYWORDS: SQLITE_TRACE 3548 ** 3549 ** These constants identify classes of events that can be monitored 3550 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3551 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3552 ** the following constants. ^The first argument to the trace callback 3553 ** is one of the following constants. 3554 ** 3555 ** New tracing constants may be added in future releases. 3556 ** 3557 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3558 ** ^The T argument is one of the integer type codes above. 3559 ** ^The C argument is a copy of the context pointer passed in as the 3560 ** fourth argument to [sqlite3_trace_v2()]. 3561 ** The P and X arguments are pointers whose meanings depend on T. 3562 ** 3563 ** <dl> 3564 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3565 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3566 ** first begins running and possibly at other times during the 3567 ** execution of the prepared statement, such as at the start of each 3568 ** trigger subprogram. ^The P argument is a pointer to the 3569 ** [prepared statement]. ^The X argument is a pointer to a string which 3570 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3571 ** that indicates the invocation of a trigger. ^The callback can compute 3572 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3573 ** interface by using the X argument when X begins with "--" and invoking 3574 ** [sqlite3_expanded_sql(P)] otherwise. 3575 ** 3576 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3577 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3578 ** information as is provided by the [sqlite3_profile()] callback. 3579 ** ^The P argument is a pointer to the [prepared statement] and the 3580 ** X argument points to a 64-bit integer which is approximately 3581 ** the number of nanoseconds that the prepared statement took to run. 3582 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3583 ** 3584 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3585 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3586 ** statement generates a single row of result. 3587 ** ^The P argument is a pointer to the [prepared statement] and the 3588 ** X argument is unused. 3589 ** 3590 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3591 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3592 ** connection closes. 3593 ** ^The P argument is a pointer to the [database connection] object 3594 ** and the X argument is unused. 3595 ** </dl> 3596 */ 3597 #define SQLITE_TRACE_STMT 0x01 3598 #define SQLITE_TRACE_PROFILE 0x02 3599 #define SQLITE_TRACE_ROW 0x04 3600 #define SQLITE_TRACE_CLOSE 0x08 3601 3602 /* 3603 ** CAPI3REF: SQL Trace Hook 3604 ** METHOD: sqlite3 3605 ** 3606 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3607 ** function X against [database connection] D, using property mask M 3608 ** and context pointer P. ^If the X callback is 3609 ** NULL or if the M mask is zero, then tracing is disabled. The 3610 ** M argument should be the bitwise OR-ed combination of 3611 ** zero or more [SQLITE_TRACE] constants. 3612 ** 3613 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P) 3614 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or 3615 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each 3616 ** database connection may have at most one trace callback. 3617 ** 3618 ** ^The X callback is invoked whenever any of the events identified by 3619 ** mask M occur. ^The integer return value from the callback is currently 3620 ** ignored, though this may change in future releases. Callback 3621 ** implementations should return zero to ensure future compatibility. 3622 ** 3623 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3624 ** ^The T argument is one of the [SQLITE_TRACE] 3625 ** constants to indicate why the callback was invoked. 3626 ** ^The C argument is a copy of the context pointer. 3627 ** The P and X arguments are pointers whose meanings depend on T. 3628 ** 3629 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3630 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3631 ** are deprecated. 3632 */ 3633 SQLITE_API int sqlite3_trace_v2( 3634 sqlite3*, 3635 unsigned uMask, 3636 int(*xCallback)(unsigned,void*,void*,void*), 3637 void *pCtx 3638 ); 3639 3640 /* 3641 ** CAPI3REF: Query Progress Callbacks 3642 ** METHOD: sqlite3 3643 ** 3644 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3645 ** function X to be invoked periodically during long running calls to 3646 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for 3647 ** database connection D. An example use for this 3648 ** interface is to keep a GUI updated during a large query. 3649 ** 3650 ** ^The parameter P is passed through as the only parameter to the 3651 ** callback function X. ^The parameter N is the approximate number of 3652 ** [virtual machine instructions] that are evaluated between successive 3653 ** invocations of the callback X. ^If N is less than one then the progress 3654 ** handler is disabled. 3655 ** 3656 ** ^Only a single progress handler may be defined at one time per 3657 ** [database connection]; setting a new progress handler cancels the 3658 ** old one. ^Setting parameter X to NULL disables the progress handler. 3659 ** ^The progress handler is also disabled by setting N to a value less 3660 ** than 1. 3661 ** 3662 ** ^If the progress callback returns non-zero, the operation is 3663 ** interrupted. This feature can be used to implement a 3664 ** "Cancel" button on a GUI progress dialog box. 3665 ** 3666 ** The progress handler callback must not do anything that will modify 3667 ** the database connection that invoked the progress handler. 3668 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3669 ** database connections for the meaning of "modify" in this paragraph. 3670 ** 3671 ** The progress handler callback would originally only be invoked from the 3672 ** bytecode engine. It still might be invoked during [sqlite3_prepare()] 3673 ** and similar because those routines might force a reparse of the schema 3674 ** which involves running the bytecode engine. However, beginning with 3675 ** SQLite version 3.41.0, the progress handler callback might also be 3676 ** invoked directly from [sqlite3_prepare()] while analyzing and generating 3677 ** code for complex queries. 3678 */ 3679 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3680 3681 /* 3682 ** CAPI3REF: Opening A New Database Connection 3683 ** CONSTRUCTOR: sqlite3 3684 ** 3685 ** ^These routines open an SQLite database file as specified by the 3686 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3687 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3688 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3689 ** returned in *ppDb, even if an error occurs. The only exception is that 3690 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3691 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3692 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3693 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3694 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3695 ** an English language description of the error following a failure of any 3696 ** of the sqlite3_open() routines. 3697 ** 3698 ** ^The default encoding will be UTF-8 for databases created using 3699 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3700 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3701 ** 3702 ** Whether or not an error occurs when it is opened, resources 3703 ** associated with the [database connection] handle should be released by 3704 ** passing it to [sqlite3_close()] when it is no longer required. 3705 ** 3706 ** The sqlite3_open_v2() interface works like sqlite3_open() 3707 ** except that it accepts two additional parameters for additional control 3708 ** over the new database connection. ^(The flags parameter to 3709 ** sqlite3_open_v2() must include, at a minimum, one of the following 3710 ** three flag combinations:)^ 3711 ** 3712 ** <dl> 3713 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3714 ** <dd>The database is opened in read-only mode. If the database does 3715 ** not already exist, an error is returned.</dd>)^ 3716 ** 3717 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3718 ** <dd>The database is opened for reading and writing if possible, or 3719 ** reading only if the file is write protected by the operating 3720 ** system. In either case the database must already exist, otherwise 3721 ** an error is returned. For historical reasons, if opening in 3722 ** read-write mode fails due to OS-level permissions, an attempt is 3723 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be 3724 ** used to determine whether the database is actually 3725 ** read-write.</dd>)^ 3726 ** 3727 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3728 ** <dd>The database is opened for reading and writing, and is created if 3729 ** it does not already exist. This is the behavior that is always used for 3730 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3731 ** </dl> 3732 ** 3733 ** In addition to the required flags, the following optional flags are 3734 ** also supported: 3735 ** 3736 ** <dl> 3737 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3738 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3739 ** 3740 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3741 ** <dd>The database will be opened as an in-memory database. The database 3742 ** is named by the "filename" argument for the purposes of cache-sharing, 3743 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3744 ** </dd>)^ 3745 ** 3746 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3747 ** <dd>The new database connection will use the "multi-thread" 3748 ** [threading mode].)^ This means that separate threads are allowed 3749 ** to use SQLite at the same time, as long as each thread is using 3750 ** a different [database connection]. 3751 ** 3752 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3753 ** <dd>The new database connection will use the "serialized" 3754 ** [threading mode].)^ This means the multiple threads can safely 3755 ** attempt to use the same database connection at the same time. 3756 ** (Mutexes will block any actual concurrency, but in this mode 3757 ** there is no harm in trying.) 3758 ** 3759 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3760 ** <dd>The database is opened with [shared cache] enabled, overriding 3761 ** the default shared cache setting provided by 3762 ** [sqlite3_enable_shared_cache()].)^ 3763 ** The [use of shared cache mode is discouraged] and hence shared cache 3764 ** capabilities may be omitted from many builds of SQLite. In such cases, 3765 ** this option is a no-op. 3766 ** 3767 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3768 ** <dd>The database is opened with [shared cache] disabled, overriding 3769 ** the default shared cache setting provided by 3770 ** [sqlite3_enable_shared_cache()].)^ 3771 ** 3772 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3773 ** <dd>The database connection comes up in "extended result code mode". 3774 ** In other words, the database behaves as if 3775 ** [sqlite3_extended_result_codes(db,1)] were called on the database 3776 ** connection as soon as the connection is created. In addition to setting 3777 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3778 ** to return an extended result code.</dd> 3779 ** 3780 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3781 ** <dd>The database filename is not allowed to contain a symbolic link</dd> 3782 ** </dl>)^ 3783 ** 3784 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3785 ** required combinations shown above optionally combined with other 3786 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3787 ** then the behavior is undefined. Historic versions of SQLite 3788 ** have silently ignored surplus bits in the flags parameter to 3789 ** sqlite3_open_v2(), however that behavior might not be carried through 3790 ** into future versions of SQLite and so applications should not rely 3791 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3792 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3793 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3794 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3795 ** by sqlite3_open_v2(). 3796 ** 3797 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3798 ** [sqlite3_vfs] object that defines the operating system interface that 3799 ** the new database connection should use. ^If the fourth parameter is 3800 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3801 ** 3802 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3803 ** is created for the connection. ^This in-memory database will vanish when 3804 ** the database connection is closed. Future versions of SQLite might 3805 ** make use of additional special filenames that begin with the ":" character. 3806 ** It is recommended that when a database filename actually does begin with 3807 ** a ":" character you should prefix the filename with a pathname such as 3808 ** "./" to avoid ambiguity. 3809 ** 3810 ** ^If the filename is an empty string, then a private, temporary 3811 ** on-disk database will be created. ^This private database will be 3812 ** automatically deleted as soon as the database connection is closed. 3813 ** 3814 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3815 ** 3816 ** ^If [URI filename] interpretation is enabled, and the filename argument 3817 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3818 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3819 ** set in the third argument to sqlite3_open_v2(), or if it has 3820 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3821 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3822 ** URI filename interpretation is turned off 3823 ** by default, but future releases of SQLite might enable URI filename 3824 ** interpretation by default. See "[URI filenames]" for additional 3825 ** information. 3826 ** 3827 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3828 ** authority, then it must be either an empty string or the string 3829 ** "localhost". ^If the authority is not an empty string or "localhost", an 3830 ** error is returned to the caller. ^The fragment component of a URI, if 3831 ** present, is ignored. 3832 ** 3833 ** ^SQLite uses the path component of the URI as the name of the disk file 3834 ** which contains the database. ^If the path begins with a '/' character, 3835 ** then it is interpreted as an absolute path. ^If the path does not begin 3836 ** with a '/' (meaning that the authority section is omitted from the URI) 3837 ** then the path is interpreted as a relative path. 3838 ** ^(On windows, the first component of an absolute path 3839 ** is a drive specification (e.g. "C:").)^ 3840 ** 3841 ** [[core URI query parameters]] 3842 ** The query component of a URI may contain parameters that are interpreted 3843 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3844 ** SQLite and its built-in [VFSes] interpret the 3845 ** following query parameters: 3846 ** 3847 ** <ul> 3848 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3849 ** a VFS object that provides the operating system interface that should 3850 ** be used to access the database file on disk. ^If this option is set to 3851 ** an empty string the default VFS object is used. ^Specifying an unknown 3852 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3853 ** present, then the VFS specified by the option takes precedence over 3854 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3855 ** 3856 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3857 ** "rwc", or "memory". Attempting to set it to any other value is 3858 ** an error)^. 3859 ** ^If "ro" is specified, then the database is opened for read-only 3860 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3861 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3862 ** "rw", then the database is opened for read-write (but not create) 3863 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3864 ** been set. ^Value "rwc" is equivalent to setting both 3865 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3866 ** set to "memory" then a pure [in-memory database] that never reads 3867 ** or writes from disk is used. ^It is an error to specify a value for 3868 ** the mode parameter that is less restrictive than that specified by 3869 ** the flags passed in the third parameter to sqlite3_open_v2(). 3870 ** 3871 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3872 ** "private". ^Setting it to "shared" is equivalent to setting the 3873 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3874 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3875 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3876 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3877 ** a URI filename, its value overrides any behavior requested by setting 3878 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3879 ** 3880 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3881 ** [powersafe overwrite] property does or does not apply to the 3882 ** storage media on which the database file resides. 3883 ** 3884 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3885 ** which if set disables file locking in rollback journal modes. This 3886 ** is useful for accessing a database on a filesystem that does not 3887 ** support locking. Caution: Database corruption might result if two 3888 ** or more processes write to the same database and any one of those 3889 ** processes uses nolock=1. 3890 ** 3891 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3892 ** parameter that indicates that the database file is stored on 3893 ** read-only media. ^When immutable is set, SQLite assumes that the 3894 ** database file cannot be changed, even by a process with higher 3895 ** privilege, and so the database is opened read-only and all locking 3896 ** and change detection is disabled. Caution: Setting the immutable 3897 ** property on a database file that does in fact change can result 3898 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3899 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3900 ** 3901 ** </ul> 3902 ** 3903 ** ^Specifying an unknown parameter in the query component of a URI is not an 3904 ** error. Future versions of SQLite might understand additional query 3905 ** parameters. See "[query parameters with special meaning to SQLite]" for 3906 ** additional information. 3907 ** 3908 ** [[URI filename examples]] <h3>URI filename examples</h3> 3909 ** 3910 ** <table border="1" align=center cellpadding=5> 3911 ** <tr><th> URI filenames <th> Results 3912 ** <tr><td> file:data.db <td> 3913 ** Open the file "data.db" in the current directory. 3914 ** <tr><td> file:/home/fred/data.db<br> 3915 ** file:///home/fred/data.db <br> 3916 ** file://localhost/home/fred/data.db <br> <td> 3917 ** Open the database file "/home/fred/data.db". 3918 ** <tr><td> file://darkstar/home/fred/data.db <td> 3919 ** An error. "darkstar" is not a recognized authority. 3920 ** <tr><td style="white-space:nowrap"> 3921 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3922 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3923 ** C:. Note that the %20 escaping in this example is not strictly 3924 ** necessary - space characters can be used literally 3925 ** in URI filenames. 3926 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3927 ** Open file "data.db" in the current directory for read-only access. 3928 ** Regardless of whether or not shared-cache mode is enabled by 3929 ** default, use a private cache. 3930 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3931 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3932 ** that uses dot-files in place of posix advisory locking. 3933 ** <tr><td> file:data.db?mode=readonly <td> 3934 ** An error. "readonly" is not a valid option for the "mode" parameter. 3935 ** Use "ro" instead: "file:data.db?mode=ro". 3936 ** </table> 3937 ** 3938 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3939 ** query components of a URI. A hexadecimal escape sequence consists of a 3940 ** percent sign - "%" - followed by exactly two hexadecimal digits 3941 ** specifying an octet value. ^Before the path or query components of a 3942 ** URI filename are interpreted, they are encoded using UTF-8 and all 3943 ** hexadecimal escape sequences replaced by a single byte containing the 3944 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3945 ** the results are undefined. 3946 ** 3947 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3948 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3949 ** codepage is currently defined. Filenames containing international 3950 ** characters must be converted to UTF-8 prior to passing them into 3951 ** sqlite3_open() or sqlite3_open_v2(). 3952 ** 3953 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3954 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3955 ** features that require the use of temporary files may fail. 3956 ** 3957 ** See also: [sqlite3_temp_directory] 3958 */ 3959 SQLITE_API int sqlite3_open( 3960 const char *filename, /* Database filename (UTF-8) */ 3961 sqlite3 **ppDb /* OUT: SQLite db handle */ 3962 ); 3963 SQLITE_API int sqlite3_open16( 3964 const void *filename, /* Database filename (UTF-16) */ 3965 sqlite3 **ppDb /* OUT: SQLite db handle */ 3966 ); 3967 SQLITE_API int sqlite3_open_v2( 3968 const char *filename, /* Database filename (UTF-8) */ 3969 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3970 int flags, /* Flags */ 3971 const char *zVfs /* Name of VFS module to use */ 3972 ); 3973 3974 /* 3975 ** CAPI3REF: Obtain Values For URI Parameters 3976 ** 3977 ** These are utility routines, useful to [VFS|custom VFS implementations], 3978 ** that check if a database file was a URI that contained a specific query 3979 ** parameter, and if so obtains the value of that query parameter. 3980 ** 3981 ** The first parameter to these interfaces (hereafter referred to 3982 ** as F) must be one of: 3983 ** <ul> 3984 ** <li> A database filename pointer created by the SQLite core and 3985 ** passed into the xOpen() method of a VFS implementation, or 3986 ** <li> A filename obtained from [sqlite3_db_filename()], or 3987 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3988 ** </ul> 3989 ** If the F parameter is not one of the above, then the behavior is 3990 ** undefined and probably undesirable. Older versions of SQLite were 3991 ** more tolerant of invalid F parameters than newer versions. 3992 ** 3993 ** If F is a suitable filename (as described in the previous paragraph) 3994 ** and if P is the name of the query parameter, then 3995 ** sqlite3_uri_parameter(F,P) returns the value of the P 3996 ** parameter if it exists or a NULL pointer if P does not appear as a 3997 ** query parameter on F. If P is a query parameter of F and it 3998 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3999 ** a pointer to an empty string. 4000 ** 4001 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 4002 ** parameter and returns true (1) or false (0) according to the value 4003 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 4004 ** value of query parameter P is one of "yes", "true", or "on" in any 4005 ** case or if the value begins with a non-zero number. The 4006 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 4007 ** query parameter P is one of "no", "false", or "off" in any case or 4008 ** if the value begins with a numeric zero. If P is not a query 4009 ** parameter on F or if the value of P does not match any of the 4010 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 4011 ** 4012 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 4013 ** 64-bit signed integer and returns that integer, or D if P does not 4014 ** exist. If the value of P is something other than an integer, then 4015 ** zero is returned. 4016 ** 4017 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 4018 ** the value) of the N-th query parameter for filename F, or a NULL 4019 ** pointer if N is less than zero or greater than the number of query 4020 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 4021 ** the name of the first query parameter, 1 for the second parameter, and 4022 ** so forth. 4023 ** 4024 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 4025 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 4026 ** is not a database file pathname pointer that the SQLite core passed 4027 ** into the xOpen VFS method, then the behavior of this routine is undefined 4028 ** and probably undesirable. 4029 ** 4030 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 4031 ** parameter can also be the name of a rollback journal file or WAL file 4032 ** in addition to the main database file. Prior to version 3.31.0, these 4033 ** routines would only work if F was the name of the main database file. 4034 ** When the F parameter is the name of the rollback journal or WAL file, 4035 ** it has access to all the same query parameters as were found on the 4036 ** main database file. 4037 ** 4038 ** See the [URI filename] documentation for additional information. 4039 */ 4040 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 4041 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 4042 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 4043 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 4044 4045 /* 4046 ** CAPI3REF: Translate filenames 4047 ** 4048 ** These routines are available to [VFS|custom VFS implementations] for 4049 ** translating filenames between the main database file, the journal file, 4050 ** and the WAL file. 4051 ** 4052 ** If F is the name of an sqlite database file, journal file, or WAL file 4053 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 4054 ** returns the name of the corresponding database file. 4055 ** 4056 ** If F is the name of an sqlite database file, journal file, or WAL file 4057 ** passed by the SQLite core into the VFS, or if F is a database filename 4058 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 4059 ** returns the name of the corresponding rollback journal file. 4060 ** 4061 ** If F is the name of an sqlite database file, journal file, or WAL file 4062 ** that was passed by the SQLite core into the VFS, or if F is a database 4063 ** filename obtained from [sqlite3_db_filename()], then 4064 ** sqlite3_filename_wal(F) returns the name of the corresponding 4065 ** WAL file. 4066 ** 4067 ** In all of the above, if F is not the name of a database, journal or WAL 4068 ** filename passed into the VFS from the SQLite core and F is not the 4069 ** return value from [sqlite3_db_filename()], then the result is 4070 ** undefined and is likely a memory access violation. 4071 */ 4072 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 4073 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 4074 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 4075 4076 /* 4077 ** CAPI3REF: Database File Corresponding To A Journal 4078 ** 4079 ** ^If X is the name of a rollback or WAL-mode journal file that is 4080 ** passed into the xOpen method of [sqlite3_vfs], then 4081 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 4082 ** object that represents the main database file. 4083 ** 4084 ** This routine is intended for use in custom [VFS] implementations 4085 ** only. It is not a general-purpose interface. 4086 ** The argument sqlite3_file_object(X) must be a filename pointer that 4087 ** has been passed into [sqlite3_vfs].xOpen method where the 4088 ** flags parameter to xOpen contains one of the bits 4089 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 4090 ** of this routine results in undefined and probably undesirable 4091 ** behavior. 4092 */ 4093 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 4094 4095 /* 4096 ** CAPI3REF: Create and Destroy VFS Filenames 4097 ** 4098 ** These interfaces are provided for use by [VFS shim] implementations and 4099 ** are not useful outside of that context. 4100 ** 4101 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 4102 ** database filename D with corresponding journal file J and WAL file W and 4103 ** an array P of N URI Key/Value pairs. The result from 4104 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 4105 ** is safe to pass to routines like: 4106 ** <ul> 4107 ** <li> [sqlite3_uri_parameter()], 4108 ** <li> [sqlite3_uri_boolean()], 4109 ** <li> [sqlite3_uri_int64()], 4110 ** <li> [sqlite3_uri_key()], 4111 ** <li> [sqlite3_filename_database()], 4112 ** <li> [sqlite3_filename_journal()], or 4113 ** <li> [sqlite3_filename_wal()]. 4114 ** </ul> 4115 ** If a memory allocation error occurs, sqlite3_create_filename() might 4116 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 4117 ** must be released by a corresponding call to sqlite3_free_filename(Y). 4118 ** 4119 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 4120 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 4121 ** to a key and value for a query parameter. The P parameter may be a NULL 4122 ** pointer if N is zero. None of the 2*N pointers in the P array may be 4123 ** NULL pointers and key pointers should not be empty strings. 4124 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 4125 ** be NULL pointers, though they can be empty strings. 4126 ** 4127 ** The sqlite3_free_filename(Y) routine releases a memory allocation 4128 ** previously obtained from sqlite3_create_filename(). Invoking 4129 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 4130 ** 4131 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 4132 ** than a NULL pointer or a pointer previously acquired from 4133 ** sqlite3_create_filename(), then bad things such as heap 4134 ** corruption or segfaults may occur. The value Y should not be 4135 ** used again after sqlite3_free_filename(Y) has been called. This means 4136 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 4137 ** then the corresponding [sqlite3_module.xClose() method should also be 4138 ** invoked prior to calling sqlite3_free_filename(Y). 4139 */ 4140 SQLITE_API sqlite3_filename sqlite3_create_filename( 4141 const char *zDatabase, 4142 const char *zJournal, 4143 const char *zWal, 4144 int nParam, 4145 const char **azParam 4146 ); 4147 SQLITE_API void sqlite3_free_filename(sqlite3_filename); 4148 4149 /* 4150 ** CAPI3REF: Error Codes And Messages 4151 ** METHOD: sqlite3 4152 ** 4153 ** ^If the most recent sqlite3_* API call associated with 4154 ** [database connection] D failed, then the sqlite3_errcode(D) interface 4155 ** returns the numeric [result code] or [extended result code] for that 4156 ** API call. 4157 ** ^The sqlite3_extended_errcode() 4158 ** interface is the same except that it always returns the 4159 ** [extended result code] even when extended result codes are 4160 ** disabled. 4161 ** 4162 ** The values returned by sqlite3_errcode() and/or 4163 ** sqlite3_extended_errcode() might change with each API call. 4164 ** Except, there are some interfaces that are guaranteed to never 4165 ** change the value of the error code. The error-code preserving 4166 ** interfaces include the following: 4167 ** 4168 ** <ul> 4169 ** <li> sqlite3_errcode() 4170 ** <li> sqlite3_extended_errcode() 4171 ** <li> sqlite3_errmsg() 4172 ** <li> sqlite3_errmsg16() 4173 ** <li> sqlite3_error_offset() 4174 ** </ul> 4175 ** 4176 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 4177 ** text that describes the error, as either UTF-8 or UTF-16 respectively, 4178 ** or NULL if no error message is available. 4179 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.) 4180 ** ^(Memory to hold the error message string is managed internally. 4181 ** The application does not need to worry about freeing the result. 4182 ** However, the error string might be overwritten or deallocated by 4183 ** subsequent calls to other SQLite interface functions.)^ 4184 ** 4185 ** ^The sqlite3_errstr(E) interface returns the English-language text 4186 ** that describes the [result code] E, as UTF-8, or NULL if E is not a 4187 ** result code for which a text error message is available. 4188 ** ^(Memory to hold the error message string is managed internally 4189 ** and must not be freed by the application)^. 4190 ** 4191 ** ^If the most recent error references a specific token in the input 4192 ** SQL, the sqlite3_error_offset() interface returns the byte offset 4193 ** of the start of that token. ^The byte offset returned by 4194 ** sqlite3_error_offset() assumes that the input SQL is UTF-8. 4195 ** ^If the most recent error does not reference a specific token in the input 4196 ** SQL, then the sqlite3_error_offset() function returns -1. 4197 ** 4198 ** When the serialized [threading mode] is in use, it might be the 4199 ** case that a second error occurs on a separate thread in between 4200 ** the time of the first error and the call to these interfaces. 4201 ** When that happens, the second error will be reported since these 4202 ** interfaces always report the most recent result. To avoid 4203 ** this, each thread can obtain exclusive use of the [database connection] D 4204 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 4205 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 4206 ** all calls to the interfaces listed here are completed. 4207 ** 4208 ** If an interface fails with SQLITE_MISUSE, that means the interface 4209 ** was invoked incorrectly by the application. In that case, the 4210 ** error code and message may or may not be set. 4211 */ 4212 SQLITE_API int sqlite3_errcode(sqlite3 *db); 4213 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 4214 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 4215 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 4216 SQLITE_API const char *sqlite3_errstr(int); 4217 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 4218 4219 /* 4220 ** CAPI3REF: Set Error Codes And Message 4221 ** METHOD: sqlite3 4222 ** 4223 ** Set the error code of the database handle passed as the first argument 4224 ** to errcode, and the error message to a copy of nul-terminated string 4225 ** zErrMsg. If zErrMsg is passed NULL, then the error message is set to 4226 ** the default message associated with the supplied error code. Subsequent 4227 ** calls to [sqlite3_errcode()] and [sqlite3_errmsg()] and similar will 4228 ** return the values set by this routine in place of what was previously 4229 ** set by SQLite itself. 4230 ** 4231 ** This function returns SQLITE_OK if the error code and error message are 4232 ** successfully set, SQLITE_NOMEM if an OOM occurs, and SQLITE_MISUSE if 4233 ** the database handle is NULL or invalid. 4234 ** 4235 ** The error code and message set by this routine remains in effect until 4236 ** they are changed, either by another call to this routine or until they are 4237 ** changed to by SQLite itself to reflect the result of some subsquent 4238 ** API call. 4239 ** 4240 ** This function is intended for use by SQLite extensions or wrappers. The 4241 ** idea is that an extension or wrapper can use this routine to set error 4242 ** messages and error codes and thus behave more like a core SQLite 4243 ** feature from the point of view of an application. 4244 */ 4245 SQLITE_API int sqlite3_set_errmsg(sqlite3 *db, int errcode, const char *zErrMsg); 4246 4247 /* 4248 ** CAPI3REF: Prepared Statement Object 4249 ** KEYWORDS: {prepared statement} {prepared statements} 4250 ** 4251 ** An instance of this object represents a single SQL statement that 4252 ** has been compiled into binary form and is ready to be evaluated. 4253 ** 4254 ** Think of each SQL statement as a separate computer program. The 4255 ** original SQL text is source code. A prepared statement object 4256 ** is the compiled object code. All SQL must be converted into a 4257 ** prepared statement before it can be run. 4258 ** 4259 ** The life-cycle of a prepared statement object usually goes like this: 4260 ** 4261 ** <ol> 4262 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 4263 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 4264 ** interfaces. 4265 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 4266 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 4267 ** to step 2. Do this zero or more times. 4268 ** <li> Destroy the object using [sqlite3_finalize()]. 4269 ** </ol> 4270 */ 4271 typedef struct sqlite3_stmt sqlite3_stmt; 4272 4273 /* 4274 ** CAPI3REF: Run-time Limits 4275 ** METHOD: sqlite3 4276 ** 4277 ** ^(This interface allows the size of various constructs to be limited 4278 ** on a connection by connection basis. The first parameter is the 4279 ** [database connection] whose limit is to be set or queried. The 4280 ** second parameter is one of the [limit categories] that define a 4281 ** class of constructs to be size limited. The third parameter is the 4282 ** new limit for that construct.)^ 4283 ** 4284 ** ^If the new limit is a negative number, the limit is unchanged. 4285 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 4286 ** [limits | hard upper bound] 4287 ** set at compile-time by a C preprocessor macro called 4288 ** [limits | SQLITE_MAX_<i>NAME</i>]. 4289 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 4290 ** ^Attempts to increase a limit above its hard upper bound are 4291 ** silently truncated to the hard upper bound. 4292 ** 4293 ** ^Regardless of whether or not the limit was changed, the 4294 ** [sqlite3_limit()] interface returns the prior value of the limit. 4295 ** ^Hence, to find the current value of a limit without changing it, 4296 ** simply invoke this interface with the third parameter set to -1. 4297 ** 4298 ** Run-time limits are intended for use in applications that manage 4299 ** both their own internal database and also databases that are controlled 4300 ** by untrusted external sources. An example application might be a 4301 ** web browser that has its own databases for storing history and 4302 ** separate databases controlled by JavaScript applications downloaded 4303 ** off the Internet. The internal databases can be given the 4304 ** large, default limits. Databases managed by external sources can 4305 ** be given much smaller limits designed to prevent a denial of service 4306 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 4307 ** interface to further control untrusted SQL. The size of the database 4308 ** created by an untrusted script can be contained using the 4309 ** [max_page_count] [PRAGMA]. 4310 ** 4311 ** New run-time limit categories may be added in future releases. 4312 */ 4313 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 4314 4315 /* 4316 ** CAPI3REF: Run-Time Limit Categories 4317 ** KEYWORDS: {limit category} {*limit categories} 4318 ** 4319 ** These constants define various performance limits 4320 ** that can be lowered at run-time using [sqlite3_limit()]. 4321 ** A concise description of these limits follows, and additional information 4322 ** is available at [limits | Limits in SQLite]. 4323 ** 4324 ** <dl> 4325 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 4326 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 4327 ** 4328 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 4329 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 4330 ** 4331 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 4332 ** <dd>The maximum number of columns in a table definition or in the 4333 ** result set of a [SELECT] or the maximum number of columns in an index 4334 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 4335 ** 4336 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4337 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4338 ** 4339 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4340 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4341 ** 4342 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4343 ** <dd>The maximum number of instructions in a virtual machine program 4344 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4345 ** the equivalent tries to allocate space for more than this many opcodes 4346 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4347 ** 4348 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4349 ** <dd>The maximum number of arguments on a function.</dd>)^ 4350 ** 4351 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4352 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4353 ** 4354 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4355 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4356 ** <dd>The maximum length of the pattern argument to the [LIKE] or 4357 ** [GLOB] operators.</dd>)^ 4358 ** 4359 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4360 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4361 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4362 ** 4363 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4364 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 4365 ** 4366 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4367 ** <dd>The maximum number of auxiliary worker threads that a single 4368 ** [prepared statement] may start.</dd>)^ 4369 ** </dl> 4370 */ 4371 #define SQLITE_LIMIT_LENGTH 0 4372 #define SQLITE_LIMIT_SQL_LENGTH 1 4373 #define SQLITE_LIMIT_COLUMN 2 4374 #define SQLITE_LIMIT_EXPR_DEPTH 3 4375 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4376 #define SQLITE_LIMIT_VDBE_OP 5 4377 #define SQLITE_LIMIT_FUNCTION_ARG 6 4378 #define SQLITE_LIMIT_ATTACHED 7 4379 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4380 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4381 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4382 #define SQLITE_LIMIT_WORKER_THREADS 11 4383 4384 /* 4385 ** CAPI3REF: Prepare Flags 4386 ** 4387 ** These constants define various flags that can be passed into the 4388 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4389 ** [sqlite3_prepare16_v3()] interfaces. 4390 ** 4391 ** New flags may be added in future releases of SQLite. 4392 ** 4393 ** <dl> 4394 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4395 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4396 ** that the prepared statement will be retained for a long time and 4397 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4398 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4399 ** be used just once or at most a few times and then destroyed using 4400 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4401 ** on this hint by avoiding the use of [lookaside memory] so as not to 4402 ** deplete the limited store of lookaside memory. Future versions of 4403 ** SQLite may act on this hint differently. 4404 ** 4405 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4406 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4407 ** to be required for any prepared statement that wanted to use the 4408 ** [sqlite3_normalized_sql()] interface. However, the 4409 ** [sqlite3_normalized_sql()] interface is now available to all 4410 ** prepared statements, regardless of whether or not they use this 4411 ** flag. 4412 ** 4413 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4414 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4415 ** to return an error (error code SQLITE_ERROR) if the statement uses 4416 ** any virtual tables. 4417 ** 4418 ** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt> 4419 ** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler 4420 ** errors from being sent to the error log defined by 4421 ** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test 4422 ** compiles to see if some SQL syntax is well-formed, without generating 4423 ** messages on the global error log when it is not. If the test compile 4424 ** fails, the sqlite3_prepare_v3() call returns the same error indications 4425 ** with or without this flag; it just omits the call to [sqlite3_log()] that 4426 ** logs the error. 4427 ** </dl> 4428 */ 4429 #define SQLITE_PREPARE_PERSISTENT 0x01 4430 #define SQLITE_PREPARE_NORMALIZE 0x02 4431 #define SQLITE_PREPARE_NO_VTAB 0x04 4432 #define SQLITE_PREPARE_DONT_LOG 0x10 4433 4434 /* 4435 ** CAPI3REF: Compiling An SQL Statement 4436 ** KEYWORDS: {SQL statement compiler} 4437 ** METHOD: sqlite3 4438 ** CONSTRUCTOR: sqlite3_stmt 4439 ** 4440 ** To execute an SQL statement, it must first be compiled into a byte-code 4441 ** program using one of these routines. Or, in other words, these routines 4442 ** are constructors for the [prepared statement] object. 4443 ** 4444 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4445 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4446 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4447 ** for special purposes. 4448 ** 4449 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4450 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4451 ** as a convenience. The UTF-16 interfaces work by converting the 4452 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4453 ** 4454 ** The first argument, "db", is a [database connection] obtained from a 4455 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4456 ** [sqlite3_open16()]. The database connection must not have been closed. 4457 ** 4458 ** The second argument, "zSql", is the statement to be compiled, encoded 4459 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4460 ** and sqlite3_prepare_v3() 4461 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4462 ** and sqlite3_prepare16_v3() use UTF-16. 4463 ** 4464 ** ^If the nByte argument is negative, then zSql is read up to the 4465 ** first zero terminator. ^If nByte is positive, then it is the maximum 4466 ** number of bytes read from zSql. When nByte is positive, zSql is read 4467 ** up to the first zero terminator or until the nByte bytes have been read, 4468 ** whichever comes first. ^If nByte is zero, then no prepared 4469 ** statement is generated. 4470 ** If the caller knows that the supplied string is nul-terminated, then 4471 ** there is a small performance advantage to passing an nByte parameter that 4472 ** is the number of bytes in the input string <i>including</i> 4473 ** the nul-terminator. 4474 ** Note that nByte measures the length of the input in bytes, not 4475 ** characters, even for the UTF-16 interfaces. 4476 ** 4477 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4478 ** past the end of the first SQL statement in zSql. These routines only 4479 ** compile the first statement in zSql, so *pzTail is left pointing to 4480 ** what remains uncompiled. 4481 ** 4482 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4483 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4484 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4485 ** string or a comment) then *ppStmt is set to NULL. 4486 ** The calling procedure is responsible for deleting the compiled 4487 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4488 ** ppStmt may not be NULL. 4489 ** 4490 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4491 ** otherwise an [error code] is returned. 4492 ** 4493 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4494 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4495 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4496 ** are retained for backwards compatibility, but their use is discouraged. 4497 ** ^In the "vX" interfaces, the prepared statement 4498 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4499 ** original SQL text. This causes the [sqlite3_step()] interface to 4500 ** behave differently in three ways: 4501 ** 4502 ** <ol> 4503 ** <li> 4504 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4505 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4506 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4507 ** retries will occur before sqlite3_step() gives up and returns an error. 4508 ** </li> 4509 ** 4510 ** <li> 4511 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4512 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4513 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4514 ** and the application would have to make a second call to [sqlite3_reset()] 4515 ** in order to find the underlying cause of the problem. With the "v2" prepare 4516 ** interfaces, the underlying reason for the error is returned immediately. 4517 ** </li> 4518 ** 4519 ** <li> 4520 ** ^If the specific value bound to a [parameter | host parameter] in the 4521 ** WHERE clause might influence the choice of query plan for a statement, 4522 ** then the statement will be automatically recompiled, as if there had been 4523 ** a schema change, on the first [sqlite3_step()] call following any change 4524 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4525 ** ^The specific value of a WHERE-clause [parameter] might influence the 4526 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4527 ** or [GLOB] operator or if the parameter is compared to an indexed column 4528 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4529 ** </li> 4530 ** </ol> 4531 ** 4532 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4533 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4534 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4535 ** sqlite3_prepare_v2() interface works exactly the same as 4536 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4537 */ 4538 SQLITE_API int sqlite3_prepare( 4539 sqlite3 *db, /* Database handle */ 4540 const char *zSql, /* SQL statement, UTF-8 encoded */ 4541 int nByte, /* Maximum length of zSql in bytes. */ 4542 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4543 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4544 ); 4545 SQLITE_API int sqlite3_prepare_v2( 4546 sqlite3 *db, /* Database handle */ 4547 const char *zSql, /* SQL statement, UTF-8 encoded */ 4548 int nByte, /* Maximum length of zSql in bytes. */ 4549 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4550 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4551 ); 4552 SQLITE_API int sqlite3_prepare_v3( 4553 sqlite3 *db, /* Database handle */ 4554 const char *zSql, /* SQL statement, UTF-8 encoded */ 4555 int nByte, /* Maximum length of zSql in bytes. */ 4556 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4557 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4558 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4559 ); 4560 SQLITE_API int sqlite3_prepare16( 4561 sqlite3 *db, /* Database handle */ 4562 const void *zSql, /* SQL statement, UTF-16 encoded */ 4563 int nByte, /* Maximum length of zSql in bytes. */ 4564 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4565 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4566 ); 4567 SQLITE_API int sqlite3_prepare16_v2( 4568 sqlite3 *db, /* Database handle */ 4569 const void *zSql, /* SQL statement, UTF-16 encoded */ 4570 int nByte, /* Maximum length of zSql in bytes. */ 4571 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4572 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4573 ); 4574 SQLITE_API int sqlite3_prepare16_v3( 4575 sqlite3 *db, /* Database handle */ 4576 const void *zSql, /* SQL statement, UTF-16 encoded */ 4577 int nByte, /* Maximum length of zSql in bytes. */ 4578 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4579 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4580 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4581 ); 4582 4583 /* 4584 ** CAPI3REF: Retrieving Statement SQL 4585 ** METHOD: sqlite3_stmt 4586 ** 4587 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4588 ** SQL text used to create [prepared statement] P if P was 4589 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4590 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4591 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4592 ** string containing the SQL text of prepared statement P with 4593 ** [bound parameters] expanded. 4594 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4595 ** string containing the normalized SQL text of prepared statement P. The 4596 ** semantics used to normalize a SQL statement are unspecified and subject 4597 ** to change. At a minimum, literal values will be replaced with suitable 4598 ** placeholders. 4599 ** 4600 ** ^(For example, if a prepared statement is created using the SQL 4601 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4602 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4603 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4604 ** will return "SELECT 2345,NULL".)^ 4605 ** 4606 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4607 ** is available to hold the result, or if the result would exceed the 4608 ** maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4609 ** 4610 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4611 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4612 ** option causes sqlite3_expanded_sql() to always return NULL. 4613 ** 4614 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4615 ** are managed by SQLite and are automatically freed when the prepared 4616 ** statement is finalized. 4617 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4618 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4619 ** by passing it to [sqlite3_free()]. 4620 ** 4621 ** ^The sqlite3_normalized_sql() interface is only available if 4622 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4623 */ 4624 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4625 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4626 #ifdef SQLITE_ENABLE_NORMALIZE 4627 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4628 #endif 4629 4630 /* 4631 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4632 ** METHOD: sqlite3_stmt 4633 ** 4634 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4635 ** and only if the [prepared statement] X makes no direct changes to 4636 ** the content of the database file. 4637 ** 4638 ** Note that [application-defined SQL functions] or 4639 ** [virtual tables] might change the database indirectly as a side effect. 4640 ** ^(For example, if an application defines a function "eval()" that 4641 ** calls [sqlite3_exec()], then the following SQL statement would 4642 ** change the database file through side-effects: 4643 ** 4644 ** <blockquote><pre> 4645 ** SELECT eval('DELETE FROM t1') FROM t2; 4646 ** </pre></blockquote> 4647 ** 4648 ** But because the [SELECT] statement does not change the database file 4649 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4650 ** 4651 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4652 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4653 ** since the statements themselves do not actually modify the database but 4654 ** rather they control the timing of when other statements modify the 4655 ** database. ^The [ATTACH] and [DETACH] statements also cause 4656 ** sqlite3_stmt_readonly() to return true since, while those statements 4657 ** change the configuration of a database connection, they do not make 4658 ** changes to the content of the database files on disk. 4659 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4660 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4661 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4662 ** sqlite3_stmt_readonly() returns false for those commands. 4663 ** 4664 ** ^This routine returns false if there is any possibility that the 4665 ** statement might change the database file. ^A false return does 4666 ** not guarantee that the statement will change the database file. 4667 ** ^For example, an UPDATE statement might have a WHERE clause that 4668 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4669 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4670 ** read-only no-op if the table already exists, but 4671 ** sqlite3_stmt_readonly() still returns false for such a statement. 4672 ** 4673 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4674 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4675 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4676 */ 4677 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4678 4679 /* 4680 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4681 ** METHOD: sqlite3_stmt 4682 ** 4683 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4684 ** prepared statement S is an EXPLAIN statement, or 2 if the 4685 ** statement S is an EXPLAIN QUERY PLAN. 4686 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4687 ** an ordinary statement or a NULL pointer. 4688 */ 4689 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4690 4691 /* 4692 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement 4693 ** METHOD: sqlite3_stmt 4694 ** 4695 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN 4696 ** setting for [prepared statement] S. If E is zero, then S becomes 4697 ** a normal prepared statement. If E is 1, then S behaves as if 4698 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if 4699 ** its SQL text began with "[EXPLAIN QUERY PLAN]". 4700 ** 4701 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared. 4702 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary 4703 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode. 4704 ** 4705 ** Because of the potential need to reprepare, a call to 4706 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be 4707 ** reprepared because it was created using [sqlite3_prepare()] instead of 4708 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and 4709 ** hence has no saved SQL text with which to reprepare. 4710 ** 4711 ** Changing the explain setting for a prepared statement does not change 4712 ** the original SQL text for the statement. Hence, if the SQL text originally 4713 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0) 4714 ** is called to convert the statement into an ordinary statement, the EXPLAIN 4715 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S) 4716 ** output, even though the statement now acts like a normal SQL statement. 4717 ** 4718 ** This routine returns SQLITE_OK if the explain mode is successfully 4719 ** changed, or an error code if the explain mode could not be changed. 4720 ** The explain mode cannot be changed while a statement is active. 4721 ** Hence, it is good practice to call [sqlite3_reset(S)] 4722 ** immediately prior to calling sqlite3_stmt_explain(S,E). 4723 */ 4724 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode); 4725 4726 /* 4727 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4728 ** METHOD: sqlite3_stmt 4729 ** 4730 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4731 ** [prepared statement] S has been stepped at least once using 4732 ** [sqlite3_step(S)] but has neither run to completion (returned 4733 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4734 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4735 ** interface returns false if S is a NULL pointer. If S is not a 4736 ** NULL pointer and is not a pointer to a valid [prepared statement] 4737 ** object, then the behavior is undefined and probably undesirable. 4738 ** 4739 ** This interface can be used in combination [sqlite3_next_stmt()] 4740 ** to locate all prepared statements associated with a database 4741 ** connection that are in need of being reset. This can be used, 4742 ** for example, in diagnostic routines to search for prepared 4743 ** statements that are holding a transaction open. 4744 */ 4745 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4746 4747 /* 4748 ** CAPI3REF: Dynamically Typed Value Object 4749 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4750 ** 4751 ** SQLite uses the sqlite3_value object to represent all values 4752 ** that can be stored in a database table. SQLite uses dynamic typing 4753 ** for the values it stores. ^Values stored in sqlite3_value objects 4754 ** can be integers, floating point values, strings, BLOBs, or NULL. 4755 ** 4756 ** An sqlite3_value object may be either "protected" or "unprotected". 4757 ** Some interfaces require a protected sqlite3_value. Other interfaces 4758 ** will accept either a protected or an unprotected sqlite3_value. 4759 ** Every interface that accepts sqlite3_value arguments specifies 4760 ** whether or not it requires a protected sqlite3_value. The 4761 ** [sqlite3_value_dup()] interface can be used to construct a new 4762 ** protected sqlite3_value from an unprotected sqlite3_value. 4763 ** 4764 ** The terms "protected" and "unprotected" refer to whether or not 4765 ** a mutex is held. An internal mutex is held for a protected 4766 ** sqlite3_value object but no mutex is held for an unprotected 4767 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4768 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4769 ** or if SQLite is run in one of reduced mutex modes 4770 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4771 ** then there is no distinction between protected and unprotected 4772 ** sqlite3_value objects and they can be used interchangeably. However, 4773 ** for maximum code portability it is recommended that applications 4774 ** still make the distinction between protected and unprotected 4775 ** sqlite3_value objects even when not strictly required. 4776 ** 4777 ** ^The sqlite3_value objects that are passed as parameters into the 4778 ** implementation of [application-defined SQL functions] are protected. 4779 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4780 ** are protected. 4781 ** ^The sqlite3_value object returned by 4782 ** [sqlite3_column_value()] is unprotected. 4783 ** Unprotected sqlite3_value objects may only be used as arguments 4784 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4785 ** [sqlite3_value_dup()]. 4786 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4787 ** interfaces require protected sqlite3_value objects. 4788 */ 4789 typedef struct sqlite3_value sqlite3_value; 4790 4791 /* 4792 ** CAPI3REF: SQL Function Context Object 4793 ** 4794 ** The context in which an SQL function executes is stored in an 4795 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4796 ** is always the first parameter to [application-defined SQL functions]. 4797 ** The application-defined SQL function implementation will pass this 4798 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4799 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4800 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4801 ** and/or [sqlite3_set_auxdata()]. 4802 */ 4803 typedef struct sqlite3_context sqlite3_context; 4804 4805 /* 4806 ** CAPI3REF: Binding Values To Prepared Statements 4807 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4808 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4809 ** METHOD: sqlite3_stmt 4810 ** 4811 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4812 ** literals may be replaced by a [parameter] that matches one of the following 4813 ** templates: 4814 ** 4815 ** <ul> 4816 ** <li> ? 4817 ** <li> ?NNN 4818 ** <li> :VVV 4819 ** <li> @VVV 4820 ** <li> $VVV 4821 ** </ul> 4822 ** 4823 ** In the templates above, NNN represents an integer literal, 4824 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4825 ** parameters (also called "host parameter names" or "SQL parameters") 4826 ** can be set using the sqlite3_bind_*() routines defined here. 4827 ** 4828 ** ^The first argument to the sqlite3_bind_*() routines is always 4829 ** a pointer to the [sqlite3_stmt] object returned from 4830 ** [sqlite3_prepare_v2()] or its variants. 4831 ** 4832 ** ^The second argument is the index of the SQL parameter to be set. 4833 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4834 ** SQL parameter is used more than once, second and subsequent 4835 ** occurrences have the same index as the first occurrence. 4836 ** ^The index for named parameters can be looked up using the 4837 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4838 ** for "?NNN" parameters is the value of NNN. 4839 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4840 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4841 ** 4842 ** ^The third argument is the value to bind to the parameter. 4843 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4844 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4845 ** is ignored and the end result is the same as sqlite3_bind_null(). 4846 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4847 ** it should be a pointer to well-formed UTF8 text. 4848 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4849 ** it should be a pointer to well-formed UTF16 text. 4850 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4851 ** it should be a pointer to a well-formed unicode string that is 4852 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4853 ** otherwise. 4854 ** 4855 ** [[byte-order determination rules]] ^The byte-order of 4856 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4857 ** found in the first character, which is removed, or in the absence of a BOM 4858 ** the byte order is the native byte order of the host 4859 ** machine for sqlite3_bind_text16() or the byte order specified in 4860 ** the 6th parameter for sqlite3_bind_text64().)^ 4861 ** ^If UTF16 input text contains invalid unicode 4862 ** characters, then SQLite might change those invalid characters 4863 ** into the unicode replacement character: U+FFFD. 4864 ** 4865 ** ^(In those routines that have a fourth argument, its value is the 4866 ** number of bytes in the parameter. To be clear: the value is the 4867 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4868 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4869 ** is negative, then the length of the string is 4870 ** the number of bytes up to the first zero terminator. 4871 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4872 ** the behavior is undefined. 4873 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4874 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4875 ** that parameter must be the byte offset 4876 ** where the NUL terminator would occur assuming the string were NUL 4877 ** terminated. If any NUL characters occur at byte offsets less than 4878 ** the value of the fourth parameter then the resulting string value will 4879 ** contain embedded NULs. The result of expressions involving strings 4880 ** with embedded NULs is undefined. 4881 ** 4882 ** ^The fifth argument to the BLOB and string binding interfaces controls 4883 ** or indicates the lifetime of the object referenced by the third parameter. 4884 ** These three options exist: 4885 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4886 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4887 ** if the call to the bind API fails, except the destructor is not called if 4888 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4889 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that 4890 ** the application remains responsible for disposing of the object. ^In this 4891 ** case, the object and the provided pointer to it must remain valid until 4892 ** either the prepared statement is finalized or the same SQL parameter is 4893 ** bound to something else, whichever occurs sooner. 4894 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4895 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4896 ** object and pointer to it must remain valid until then. ^SQLite will then 4897 ** manage the lifetime of its private copy. 4898 ** 4899 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4900 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4901 ** to specify the encoding of the text in the third parameter. If 4902 ** the sixth argument to sqlite3_bind_text64() is not one of the 4903 ** allowed values shown above, or if the text encoding is different 4904 ** from the encoding specified by the sixth parameter, then the behavior 4905 ** is undefined. 4906 ** 4907 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4908 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4909 ** (just an integer to hold its size) while it is being processed. 4910 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4911 ** content is later written using 4912 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4913 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4914 ** 4915 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4916 ** [prepared statement] S to have an SQL value of NULL, but to also be 4917 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4918 ** a pointer to a destructor function for P. ^SQLite will invoke the 4919 ** destructor D with a single argument of P when it is finished using 4920 ** P, even if the call to sqlite3_bind_pointer() fails. Due to a 4921 ** historical design quirk, results are undefined if D is 4922 ** SQLITE_TRANSIENT. The T parameter should be a static string, 4923 ** preferably a string literal. The sqlite3_bind_pointer() routine is 4924 ** part of the [pointer passing interface] added for SQLite 3.20.0. 4925 ** 4926 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4927 ** for the [prepared statement] or with a prepared statement for which 4928 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4929 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4930 ** routine is passed a [prepared statement] that has been finalized, the 4931 ** result is undefined and probably harmful. 4932 ** 4933 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4934 ** ^Unbound parameters are interpreted as NULL. 4935 ** 4936 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4937 ** [error code] if anything goes wrong. 4938 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4939 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4940 ** [SQLITE_MAX_LENGTH]. 4941 ** ^[SQLITE_RANGE] is returned if the parameter 4942 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4943 ** 4944 ** See also: [sqlite3_bind_parameter_count()], 4945 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4946 */ 4947 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4948 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4949 void(*)(void*)); 4950 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4951 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4952 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4953 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4954 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4955 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4956 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4957 void(*)(void*), unsigned char encoding); 4958 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4959 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4960 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4961 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4962 4963 /* 4964 ** CAPI3REF: Number Of SQL Parameters 4965 ** METHOD: sqlite3_stmt 4966 ** 4967 ** ^This routine can be used to find the number of [SQL parameters] 4968 ** in a [prepared statement]. SQL parameters are tokens of the 4969 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4970 ** placeholders for values that are [sqlite3_bind_blob | bound] 4971 ** to the parameters at a later time. 4972 ** 4973 ** ^(This routine actually returns the index of the largest (rightmost) 4974 ** parameter. For all forms except ?NNN, this will correspond to the 4975 ** number of unique parameters. If parameters of the ?NNN form are used, 4976 ** there may be gaps in the list.)^ 4977 ** 4978 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4979 ** [sqlite3_bind_parameter_name()], and 4980 ** [sqlite3_bind_parameter_index()]. 4981 */ 4982 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4983 4984 /* 4985 ** CAPI3REF: Name Of A Host Parameter 4986 ** METHOD: sqlite3_stmt 4987 ** 4988 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4989 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4990 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4991 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4992 ** respectively. 4993 ** In other words, the initial ":" or "$" or "@" or "?" 4994 ** is included as part of the name.)^ 4995 ** ^Parameters of the form "?" without a following integer have no name 4996 ** and are referred to as "nameless" or "anonymous parameters". 4997 ** 4998 ** ^The first host parameter has an index of 1, not 0. 4999 ** 5000 ** ^If the value N is out of range or if the N-th parameter is 5001 ** nameless, then NULL is returned. ^The returned string is 5002 ** always in UTF-8 encoding even if the named parameter was 5003 ** originally specified as UTF-16 in [sqlite3_prepare16()], 5004 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 5005 ** 5006 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 5007 ** [sqlite3_bind_parameter_count()], and 5008 ** [sqlite3_bind_parameter_index()]. 5009 */ 5010 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 5011 5012 /* 5013 ** CAPI3REF: Index Of A Parameter With A Given Name 5014 ** METHOD: sqlite3_stmt 5015 ** 5016 ** ^Return the index of an SQL parameter given its name. ^The 5017 ** index value returned is suitable for use as the second 5018 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 5019 ** is returned if no matching parameter is found. ^The parameter 5020 ** name must be given in UTF-8 even if the original statement 5021 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 5022 ** [sqlite3_prepare16_v3()]. 5023 ** 5024 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 5025 ** [sqlite3_bind_parameter_count()], and 5026 ** [sqlite3_bind_parameter_name()]. 5027 */ 5028 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 5029 5030 /* 5031 ** CAPI3REF: Reset All Bindings On A Prepared Statement 5032 ** METHOD: sqlite3_stmt 5033 ** 5034 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 5035 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 5036 ** ^Use this routine to reset all host parameters to NULL. 5037 */ 5038 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 5039 5040 /* 5041 ** CAPI3REF: Number Of Columns In A Result Set 5042 ** METHOD: sqlite3_stmt 5043 ** 5044 ** ^Return the number of columns in the result set returned by the 5045 ** [prepared statement]. ^If this routine returns 0, that means the 5046 ** [prepared statement] returns no data (for example an [UPDATE]). 5047 ** ^However, just because this routine returns a positive number does not 5048 ** mean that one or more rows of data will be returned. ^A SELECT statement 5049 ** will always have a positive sqlite3_column_count() but depending on the 5050 ** WHERE clause constraints and the table content, it might return no rows. 5051 ** 5052 ** See also: [sqlite3_data_count()] 5053 */ 5054 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 5055 5056 /* 5057 ** CAPI3REF: Column Names In A Result Set 5058 ** METHOD: sqlite3_stmt 5059 ** 5060 ** ^These routines return the name assigned to a particular column 5061 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 5062 ** interface returns a pointer to a zero-terminated UTF-8 string 5063 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 5064 ** UTF-16 string. ^The first parameter is the [prepared statement] 5065 ** that implements the [SELECT] statement. ^The second parameter is the 5066 ** column number. ^The leftmost column is number 0. 5067 ** 5068 ** ^The returned string pointer is valid until either the [prepared statement] 5069 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 5070 ** reprepared by the first call to [sqlite3_step()] for a particular run 5071 ** or until the next call to 5072 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 5073 ** 5074 ** ^If sqlite3_malloc() fails during the processing of either routine 5075 ** (for example during a conversion from UTF-8 to UTF-16) then a 5076 ** NULL pointer is returned. 5077 ** 5078 ** ^The name of a result column is the value of the "AS" clause for 5079 ** that column, if there is an AS clause. If there is no AS clause 5080 ** then the name of the column is unspecified and may change from 5081 ** one release of SQLite to the next. 5082 */ 5083 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 5084 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 5085 5086 /* 5087 ** CAPI3REF: Source Of Data In A Query Result 5088 ** METHOD: sqlite3_stmt 5089 ** 5090 ** ^These routines provide a means to determine the database, table, and 5091 ** table column that is the origin of a particular result column in a 5092 ** [SELECT] statement. 5093 ** ^The name of the database or table or column can be returned as 5094 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 5095 ** the database name, the _table_ routines return the table name, and 5096 ** the origin_ routines return the column name. 5097 ** ^The returned string is valid until the [prepared statement] is destroyed 5098 ** using [sqlite3_finalize()] or until the statement is automatically 5099 ** reprepared by the first call to [sqlite3_step()] for a particular run 5100 ** or until the same information is requested 5101 ** again in a different encoding. 5102 ** 5103 ** ^The names returned are the original un-aliased names of the 5104 ** database, table, and column. 5105 ** 5106 ** ^The first argument to these interfaces is a [prepared statement]. 5107 ** ^These functions return information about the Nth result column returned by 5108 ** the statement, where N is the second function argument. 5109 ** ^The left-most column is column 0 for these routines. 5110 ** 5111 ** ^If the Nth column returned by the statement is an expression or 5112 ** subquery and is not a column value, then all of these functions return 5113 ** NULL. ^These routines might also return NULL if a memory allocation error 5114 ** occurs. ^Otherwise, they return the name of the attached database, table, 5115 ** or column that query result column was extracted from. 5116 ** 5117 ** ^As with all other SQLite APIs, those whose names end with "16" return 5118 ** UTF-16 encoded strings and the other functions return UTF-8. 5119 ** 5120 ** ^These APIs are only available if the library was compiled with the 5121 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 5122 ** 5123 ** If two or more threads call one or more 5124 ** [sqlite3_column_database_name | column metadata interfaces] 5125 ** for the same [prepared statement] and result column 5126 ** at the same time then the results are undefined. 5127 */ 5128 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 5129 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 5130 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 5131 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 5132 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 5133 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 5134 5135 /* 5136 ** CAPI3REF: Declared Datatype Of A Query Result 5137 ** METHOD: sqlite3_stmt 5138 ** 5139 ** ^(The first parameter is a [prepared statement]. 5140 ** If this statement is a [SELECT] statement and the Nth column of the 5141 ** returned result set of that [SELECT] is a table column (not an 5142 ** expression or subquery) then the declared type of the table 5143 ** column is returned.)^ ^If the Nth column of the result set is an 5144 ** expression or subquery, then a NULL pointer is returned. 5145 ** ^The returned string is always UTF-8 encoded. 5146 ** 5147 ** ^(For example, given the database schema: 5148 ** 5149 ** CREATE TABLE t1(c1 VARIANT); 5150 ** 5151 ** and the following statement to be compiled: 5152 ** 5153 ** SELECT c1 + 1, c1 FROM t1; 5154 ** 5155 ** this routine would return the string "VARIANT" for the second result 5156 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 5157 ** 5158 ** ^SQLite uses dynamic run-time typing. ^So just because a column 5159 ** is declared to contain a particular type does not mean that the 5160 ** data stored in that column is of the declared type. SQLite is 5161 ** strongly typed, but the typing is dynamic not static. ^Type 5162 ** is associated with individual values, not with the containers 5163 ** used to hold those values. 5164 */ 5165 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 5166 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 5167 5168 /* 5169 ** CAPI3REF: Evaluate An SQL Statement 5170 ** METHOD: sqlite3_stmt 5171 ** 5172 ** After a [prepared statement] has been prepared using any of 5173 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 5174 ** or [sqlite3_prepare16_v3()] or one of the legacy 5175 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 5176 ** must be called one or more times to evaluate the statement. 5177 ** 5178 ** The details of the behavior of the sqlite3_step() interface depend 5179 ** on whether the statement was prepared using the newer "vX" interfaces 5180 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 5181 ** [sqlite3_prepare16_v2()] or the older legacy 5182 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 5183 ** new "vX" interface is recommended for new applications but the legacy 5184 ** interface will continue to be supported. 5185 ** 5186 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 5187 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 5188 ** ^With the "v2" interface, any of the other [result codes] or 5189 ** [extended result codes] might be returned as well. 5190 ** 5191 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 5192 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 5193 ** or occurs outside of an explicit transaction, then you can retry the 5194 ** statement. If the statement is not a [COMMIT] and occurs within an 5195 ** explicit transaction then you should rollback the transaction before 5196 ** continuing. 5197 ** 5198 ** ^[SQLITE_DONE] means that the statement has finished executing 5199 ** successfully. sqlite3_step() should not be called again on this virtual 5200 ** machine without first calling [sqlite3_reset()] to reset the virtual 5201 ** machine back to its initial state. 5202 ** 5203 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 5204 ** is returned each time a new row of data is ready for processing by the 5205 ** caller. The values may be accessed using the [column access functions]. 5206 ** sqlite3_step() is called again to retrieve the next row of data. 5207 ** 5208 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 5209 ** violation) has occurred. sqlite3_step() should not be called again on 5210 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 5211 ** ^With the legacy interface, a more specific error code (for example, 5212 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 5213 ** can be obtained by calling [sqlite3_reset()] on the 5214 ** [prepared statement]. ^In the "v2" interface, 5215 ** the more specific error code is returned directly by sqlite3_step(). 5216 ** 5217 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 5218 ** Perhaps it was called on a [prepared statement] that has 5219 ** already been [sqlite3_finalize | finalized] or on one that had 5220 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 5221 ** be the case that the same database connection is being used by two or 5222 ** more threads at the same moment in time. 5223 ** 5224 ** For all versions of SQLite up to and including 3.6.23.1, a call to 5225 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 5226 ** other than [SQLITE_ROW] before any subsequent invocation of 5227 ** sqlite3_step(). Failure to reset the prepared statement using 5228 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 5229 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]), 5230 ** sqlite3_step() began 5231 ** calling [sqlite3_reset()] automatically in this circumstance rather 5232 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 5233 ** break because any application that ever receives an SQLITE_MISUSE error 5234 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 5235 ** can be used to restore the legacy behavior. 5236 ** 5237 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 5238 ** API always returns a generic error code, [SQLITE_ERROR], following any 5239 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 5240 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 5241 ** specific [error codes] that better describes the error. 5242 ** We admit that this is a goofy design. The problem has been fixed 5243 ** with the "v2" interface. If you prepare all of your SQL statements 5244 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 5245 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 5246 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 5247 ** then the more specific [error codes] are returned directly 5248 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 5249 */ 5250 SQLITE_API int sqlite3_step(sqlite3_stmt*); 5251 5252 /* 5253 ** CAPI3REF: Number of columns in a result set 5254 ** METHOD: sqlite3_stmt 5255 ** 5256 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 5257 ** current row of the result set of [prepared statement] P. 5258 ** ^If prepared statement P does not have results ready to return 5259 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 5260 ** interfaces) then sqlite3_data_count(P) returns 0. 5261 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 5262 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 5263 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 5264 ** will return non-zero if previous call to [sqlite3_step](P) returned 5265 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 5266 ** where it always returns zero since each step of that multi-step 5267 ** pragma returns 0 columns of data. 5268 ** 5269 ** See also: [sqlite3_column_count()] 5270 */ 5271 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 5272 5273 /* 5274 ** CAPI3REF: Fundamental Datatypes 5275 ** KEYWORDS: SQLITE_TEXT 5276 ** 5277 ** ^(Every value in SQLite has one of five fundamental datatypes: 5278 ** 5279 ** <ul> 5280 ** <li> 64-bit signed integer 5281 ** <li> 64-bit IEEE floating point number 5282 ** <li> string 5283 ** <li> BLOB 5284 ** <li> NULL 5285 ** </ul>)^ 5286 ** 5287 ** These constants are codes for each of those types. 5288 ** 5289 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 5290 ** for a completely different meaning. Software that links against both 5291 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 5292 ** SQLITE_TEXT. 5293 */ 5294 #define SQLITE_INTEGER 1 5295 #define SQLITE_FLOAT 2 5296 #define SQLITE_BLOB 4 5297 #define SQLITE_NULL 5 5298 #ifdef SQLITE_TEXT 5299 # undef SQLITE_TEXT 5300 #else 5301 # define SQLITE_TEXT 3 5302 #endif 5303 #define SQLITE3_TEXT 3 5304 5305 /* 5306 ** CAPI3REF: Result Values From A Query 5307 ** KEYWORDS: {column access functions} 5308 ** METHOD: sqlite3_stmt 5309 ** 5310 ** <b>Summary:</b> 5311 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5312 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 5313 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 5314 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 5315 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 5316 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 5317 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 5318 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 5319 ** [sqlite3_value|unprotected sqlite3_value] object. 5320 ** <tr><td> <td> <td> 5321 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 5322 ** or a UTF-8 TEXT result in bytes 5323 ** <tr><td><b>sqlite3_column_bytes16 </b> 5324 ** <td>→ <td>Size of UTF-16 5325 ** TEXT in bytes 5326 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 5327 ** datatype of the result 5328 ** </table></blockquote> 5329 ** 5330 ** <b>Details:</b> 5331 ** 5332 ** ^These routines return information about a single column of the current 5333 ** result row of a query. ^In every case the first argument is a pointer 5334 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 5335 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 5336 ** and the second argument is the index of the column for which information 5337 ** should be returned. ^The leftmost column of the result set has the index 0. 5338 ** ^The number of columns in the result can be determined using 5339 ** [sqlite3_column_count()]. 5340 ** 5341 ** If the SQL statement does not currently point to a valid row, or if the 5342 ** column index is out of range, the result is undefined. 5343 ** These routines may only be called when the most recent call to 5344 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 5345 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 5346 ** If any of these routines are called after [sqlite3_reset()] or 5347 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 5348 ** something other than [SQLITE_ROW], the results are undefined. 5349 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 5350 ** are called from a different thread while any of these routines 5351 ** are pending, then the results are undefined. 5352 ** 5353 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 5354 ** each return the value of a result column in a specific data format. If 5355 ** the result column is not initially in the requested format (for example, 5356 ** if the query returns an integer but the sqlite3_column_text() interface 5357 ** is used to extract the value) then an automatic type conversion is performed. 5358 ** 5359 ** ^The sqlite3_column_type() routine returns the 5360 ** [SQLITE_INTEGER | datatype code] for the initial data type 5361 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 5362 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 5363 ** The return value of sqlite3_column_type() can be used to decide which 5364 ** of the first six interface should be used to extract the column value. 5365 ** The value returned by sqlite3_column_type() is only meaningful if no 5366 ** automatic type conversions have occurred for the value in question. 5367 ** After a type conversion, the result of calling sqlite3_column_type() 5368 ** is undefined, though harmless. Future 5369 ** versions of SQLite may change the behavior of sqlite3_column_type() 5370 ** following a type conversion. 5371 ** 5372 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 5373 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 5374 ** of that BLOB or string. 5375 ** 5376 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 5377 ** routine returns the number of bytes in that BLOB or string. 5378 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 5379 ** the string to UTF-8 and then returns the number of bytes. 5380 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 5381 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 5382 ** the number of bytes in that string. 5383 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 5384 ** 5385 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 5386 ** routine returns the number of bytes in that BLOB or string. 5387 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5388 ** the string to UTF-16 and then returns the number of bytes. 5389 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5390 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5391 ** the number of bytes in that string. 5392 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5393 ** 5394 ** ^The values returned by [sqlite3_column_bytes()] and 5395 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5396 ** of the string. ^For clarity: the values returned by 5397 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5398 ** bytes in the string, not the number of characters. 5399 ** 5400 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5401 ** even empty strings, are always zero-terminated. ^The return 5402 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5403 ** 5404 ** ^Strings returned by sqlite3_column_text16() always have the endianness 5405 ** which is native to the platform, regardless of the text encoding set 5406 ** for the database. 5407 ** 5408 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5409 ** [unprotected sqlite3_value] object. In a multithreaded environment, 5410 ** an unprotected sqlite3_value object may only be used safely with 5411 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5412 ** If the [unprotected sqlite3_value] object returned by 5413 ** [sqlite3_column_value()] is used in any other way, including calls 5414 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5415 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5416 ** Hence, the sqlite3_column_value() interface 5417 ** is normally only useful within the implementation of 5418 ** [application-defined SQL functions] or [virtual tables], not within 5419 ** top-level application code. 5420 ** 5421 ** These routines may attempt to convert the datatype of the result. 5422 ** ^For example, if the internal representation is FLOAT and a text result 5423 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5424 ** conversion automatically. ^(The following table details the conversions 5425 ** that are applied: 5426 ** 5427 ** <blockquote> 5428 ** <table border="1"> 5429 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5430 ** 5431 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5432 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5433 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5434 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5435 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5436 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5437 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5438 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5439 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5440 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5441 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5442 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5443 ** <tr><td> TEXT <td> BLOB <td> No change 5444 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5445 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5446 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5447 ** </table> 5448 ** </blockquote>)^ 5449 ** 5450 ** Note that when type conversions occur, pointers returned by prior 5451 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5452 ** sqlite3_column_text16() may be invalidated. 5453 ** Type conversions and pointer invalidations might occur 5454 ** in the following cases: 5455 ** 5456 ** <ul> 5457 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5458 ** sqlite3_column_text16() is called. A zero-terminator might 5459 ** need to be added to the string.</li> 5460 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5461 ** sqlite3_column_text16() is called. The content must be converted 5462 ** to UTF-16.</li> 5463 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5464 ** sqlite3_column_text() is called. The content must be converted 5465 ** to UTF-8.</li> 5466 ** </ul> 5467 ** 5468 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5469 ** not invalidate a prior pointer, though of course the content of the buffer 5470 ** that the prior pointer references will have been modified. Other kinds 5471 ** of conversion are done in place when it is possible, but sometimes they 5472 ** are not possible and in those cases prior pointers are invalidated. 5473 ** 5474 ** The safest policy is to invoke these routines 5475 ** in one of the following ways: 5476 ** 5477 ** <ul> 5478 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5479 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5480 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5481 ** </ul> 5482 ** 5483 ** In other words, you should call sqlite3_column_text(), 5484 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5485 ** into the desired format, then invoke sqlite3_column_bytes() or 5486 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5487 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5488 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5489 ** with calls to sqlite3_column_bytes(). 5490 ** 5491 ** ^The pointers returned are valid until a type conversion occurs as 5492 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5493 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5494 ** and BLOBs is freed automatically. Do not pass the pointers returned 5495 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5496 ** [sqlite3_free()]. 5497 ** 5498 ** As long as the input parameters are correct, these routines will only 5499 ** fail if an out-of-memory error occurs during a format conversion. 5500 ** Only the following subset of interfaces are subject to out-of-memory 5501 ** errors: 5502 ** 5503 ** <ul> 5504 ** <li> sqlite3_column_blob() 5505 ** <li> sqlite3_column_text() 5506 ** <li> sqlite3_column_text16() 5507 ** <li> sqlite3_column_bytes() 5508 ** <li> sqlite3_column_bytes16() 5509 ** </ul> 5510 ** 5511 ** If an out-of-memory error occurs, then the return value from these 5512 ** routines is the same as if the column had contained an SQL NULL value. 5513 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5514 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5515 ** return value is obtained and before any 5516 ** other SQLite interface is called on the same [database connection]. 5517 */ 5518 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5519 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5520 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5521 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5522 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5523 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5524 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5525 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5526 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5527 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5528 5529 /* 5530 ** CAPI3REF: Destroy A Prepared Statement Object 5531 ** DESTRUCTOR: sqlite3_stmt 5532 ** 5533 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5534 ** ^If the most recent evaluation of the statement encountered no errors 5535 ** or if the statement has never been evaluated, then sqlite3_finalize() returns 5536 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5537 ** sqlite3_finalize(S) returns the appropriate [error code] or 5538 ** [extended error code]. 5539 ** 5540 ** ^The sqlite3_finalize(S) routine can be called at any point during 5541 ** the life cycle of [prepared statement] S: 5542 ** before statement S is ever evaluated, after 5543 ** one or more calls to [sqlite3_reset()], or after any call 5544 ** to [sqlite3_step()] regardless of whether or not the statement has 5545 ** completed execution. 5546 ** 5547 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5548 ** 5549 ** The application must finalize every [prepared statement] in order to avoid 5550 ** resource leaks. It is a grievous error for the application to try to use 5551 ** a prepared statement after it has been finalized. Any use of a prepared 5552 ** statement after it has been finalized can result in undefined and 5553 ** undesirable behavior such as segfaults and heap corruption. 5554 */ 5555 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5556 5557 /* 5558 ** CAPI3REF: Reset A Prepared Statement Object 5559 ** METHOD: sqlite3_stmt 5560 ** 5561 ** The sqlite3_reset() function is called to reset a [prepared statement] 5562 ** object back to its initial state, ready to be re-executed. 5563 ** ^Any SQL statement variables that had values bound to them using 5564 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5565 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5566 ** 5567 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5568 ** back to the beginning of its program. 5569 ** 5570 ** ^The return code from [sqlite3_reset(S)] indicates whether or not 5571 ** the previous evaluation of prepared statement S completed successfully. 5572 ** ^If [sqlite3_step(S)] has never before been called on S or if 5573 ** [sqlite3_step(S)] has not been called since the previous call 5574 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return 5575 ** [SQLITE_OK]. 5576 ** 5577 ** ^If the most recent call to [sqlite3_step(S)] for the 5578 ** [prepared statement] S indicated an error, then 5579 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5580 ** ^The [sqlite3_reset(S)] interface might also return an [error code] 5581 ** if there were no prior errors but the process of resetting 5582 ** the prepared statement caused a new error. ^For example, if an 5583 ** [INSERT] statement with a [RETURNING] clause is only stepped one time, 5584 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but 5585 ** the overall statement might still fail and the [sqlite3_reset(S)] call 5586 ** might return SQLITE_BUSY if locking constraints prevent the 5587 ** database change from committing. Therefore, it is important that 5588 ** applications check the return code from [sqlite3_reset(S)] even if 5589 ** no prior call to [sqlite3_step(S)] indicated a problem. 5590 ** 5591 ** ^The [sqlite3_reset(S)] interface does not change the values 5592 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5593 */ 5594 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5595 5596 5597 /* 5598 ** CAPI3REF: Create Or Redefine SQL Functions 5599 ** KEYWORDS: {function creation routines} 5600 ** METHOD: sqlite3 5601 ** 5602 ** ^These functions (collectively known as "function creation routines") 5603 ** are used to add SQL functions or aggregates or to redefine the behavior 5604 ** of existing SQL functions or aggregates. The only differences between 5605 ** the three "sqlite3_create_function*" routines are the text encoding 5606 ** expected for the second parameter (the name of the function being 5607 ** created) and the presence or absence of a destructor callback for 5608 ** the application data pointer. Function sqlite3_create_window_function() 5609 ** is similar, but allows the user to supply the extra callback functions 5610 ** needed by [aggregate window functions]. 5611 ** 5612 ** ^The first parameter is the [database connection] to which the SQL 5613 ** function is to be added. ^If an application uses more than one database 5614 ** connection then application-defined SQL functions must be added 5615 ** to each database connection separately. 5616 ** 5617 ** ^The second parameter is the name of the SQL function to be created or 5618 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5619 ** representation, exclusive of the zero-terminator. ^Note that the name 5620 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5621 ** ^Any attempt to create a function with a longer name 5622 ** will result in [SQLITE_MISUSE] being returned. 5623 ** 5624 ** ^The third parameter (nArg) 5625 ** is the number of arguments that the SQL function or 5626 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5627 ** aggregate may take any number of arguments between 0 and the limit 5628 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5629 ** parameter is less than -1 or greater than 127 then the behavior is 5630 ** undefined. 5631 ** 5632 ** ^The fourth parameter, eTextRep, specifies what 5633 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5634 ** its parameters. The application should set this parameter to 5635 ** [SQLITE_UTF16LE] if the function implementation invokes 5636 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5637 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5638 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5639 ** otherwise. ^The same SQL function may be registered multiple times using 5640 ** different preferred text encodings, with different implementations for 5641 ** each encoding. 5642 ** ^When multiple implementations of the same function are available, SQLite 5643 ** will pick the one that involves the least amount of data conversion. 5644 ** 5645 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5646 ** to signal that the function will always return the same result given 5647 ** the same inputs within a single SQL statement. Most SQL functions are 5648 ** deterministic. The built-in [random()] SQL function is an example of a 5649 ** function that is not deterministic. The SQLite query planner is able to 5650 ** perform additional optimizations on deterministic functions, so use 5651 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5652 ** 5653 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5654 ** flag, which if present prevents the function from being invoked from 5655 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5656 ** index expressions, or the WHERE clause of partial indexes. 5657 ** 5658 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5659 ** all application-defined SQL functions that do not need to be 5660 ** used inside of triggers, views, CHECK constraints, or other elements of 5661 ** the database schema. This flag is especially recommended for SQL 5662 ** functions that have side effects or reveal internal application state. 5663 ** Without this flag, an attacker might be able to modify the schema of 5664 ** a database file to include invocations of the function with parameters 5665 ** chosen by the attacker, which the application will then execute when 5666 ** the database file is opened and read. 5667 ** 5668 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5669 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5670 ** 5671 ** ^The sixth, seventh and eighth parameters passed to the three 5672 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5673 ** pointers to C-language functions that implement the SQL function or 5674 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5675 ** callback only; NULL pointers must be passed as the xStep and xFinal 5676 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5677 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5678 ** SQL function or aggregate, pass NULL pointers for all three function 5679 ** callbacks. 5680 ** 5681 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5682 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5683 ** C-language callbacks that implement the new function. xStep and xFinal 5684 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5685 ** which case a regular aggregate function is created, or must both be 5686 ** non-NULL, in which case the new function may be used as either an aggregate 5687 ** or aggregate window function. More details regarding the implementation 5688 ** of aggregate window functions are 5689 ** [user-defined window functions|available here]. 5690 ** 5691 ** ^(If the final parameter to sqlite3_create_function_v2() or 5692 ** sqlite3_create_window_function() is not NULL, then it is the destructor for 5693 ** the application data pointer. The destructor is invoked when the function 5694 ** is deleted, either by being overloaded or when the database connection 5695 ** closes.)^ ^The destructor is also invoked if the call to 5696 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5697 ** invoked, it is passed a single argument which is a copy of the application 5698 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5699 ** 5700 ** ^It is permitted to register multiple implementations of the same 5701 ** functions with the same name but with either differing numbers of 5702 ** arguments or differing preferred text encodings. ^SQLite will use 5703 ** the implementation that most closely matches the way in which the 5704 ** SQL function is used. ^A function implementation with a non-negative 5705 ** nArg parameter is a better match than a function implementation with 5706 ** a negative nArg. ^A function where the preferred text encoding 5707 ** matches the database encoding is a better 5708 ** match than a function where the encoding is different. 5709 ** ^A function where the encoding difference is between UTF16le and UTF16be 5710 ** is a closer match than a function where the encoding difference is 5711 ** between UTF8 and UTF16. 5712 ** 5713 ** ^Built-in functions may be overloaded by new application-defined functions. 5714 ** 5715 ** ^An application-defined function is permitted to call other 5716 ** SQLite interfaces. However, such calls must not 5717 ** close the database connection nor finalize or reset the prepared 5718 ** statement in which the function is running. 5719 */ 5720 SQLITE_API int sqlite3_create_function( 5721 sqlite3 *db, 5722 const char *zFunctionName, 5723 int nArg, 5724 int eTextRep, 5725 void *pApp, 5726 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5727 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5728 void (*xFinal)(sqlite3_context*) 5729 ); 5730 SQLITE_API int sqlite3_create_function16( 5731 sqlite3 *db, 5732 const void *zFunctionName, 5733 int nArg, 5734 int eTextRep, 5735 void *pApp, 5736 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5737 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5738 void (*xFinal)(sqlite3_context*) 5739 ); 5740 SQLITE_API int sqlite3_create_function_v2( 5741 sqlite3 *db, 5742 const char *zFunctionName, 5743 int nArg, 5744 int eTextRep, 5745 void *pApp, 5746 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5747 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5748 void (*xFinal)(sqlite3_context*), 5749 void(*xDestroy)(void*) 5750 ); 5751 SQLITE_API int sqlite3_create_window_function( 5752 sqlite3 *db, 5753 const char *zFunctionName, 5754 int nArg, 5755 int eTextRep, 5756 void *pApp, 5757 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5758 void (*xFinal)(sqlite3_context*), 5759 void (*xValue)(sqlite3_context*), 5760 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5761 void(*xDestroy)(void*) 5762 ); 5763 5764 /* 5765 ** CAPI3REF: Text Encodings 5766 ** 5767 ** These constants define integer codes that represent the various 5768 ** text encodings supported by SQLite. 5769 */ 5770 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5771 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5772 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5773 #define SQLITE_UTF16 4 /* Use native byte order */ 5774 #define SQLITE_ANY 5 /* Deprecated */ 5775 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5776 5777 /* 5778 ** CAPI3REF: Function Flags 5779 ** 5780 ** These constants may be ORed together with the 5781 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5782 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5783 ** [sqlite3_create_function_v2()]. 5784 ** 5785 ** <dl> 5786 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5787 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5788 ** the same output when the input parameters are the same. 5789 ** The [abs|abs() function] is deterministic, for example, but 5790 ** [randomblob|randomblob()] is not. Functions must 5791 ** be deterministic in order to be used in certain contexts such as 5792 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5793 ** SQLite might also optimize deterministic functions by factoring them 5794 ** out of inner loops. 5795 ** </dd> 5796 ** 5797 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5798 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5799 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5800 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5801 ** [expression indexes], [partial indexes], or [generated columns]. 5802 ** <p> 5803 ** The SQLITE_DIRECTONLY flag is recommended for any 5804 ** [application-defined SQL function] 5805 ** that has side-effects or that could potentially leak sensitive information. 5806 ** This will prevent attacks in which an application is tricked 5807 ** into using a database file that has had its schema surreptitiously 5808 ** modified to invoke the application-defined function in ways that are 5809 ** harmful. 5810 ** <p> 5811 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all 5812 ** [application-defined SQL functions], regardless of whether or not they 5813 ** are security sensitive, as doing so prevents those functions from being used 5814 ** inside of the database schema, and thus ensures that the database 5815 ** can be inspected and modified using generic tools (such as the [CLI]) 5816 ** that do not have access to the application-defined functions. 5817 ** </dd> 5818 ** 5819 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5820 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5821 ** to cause problems even if misused. An innocuous function should have 5822 ** no side effects and should not depend on any values other than its 5823 ** input parameters. The [abs|abs() function] is an example of an 5824 ** innocuous function. 5825 ** The [load_extension() SQL function] is not innocuous because of its 5826 ** side effects. 5827 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5828 ** exactly the same. The [random|random() function] is an example of a 5829 ** function that is innocuous but not deterministic. 5830 ** <p>Some heightened security settings 5831 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5832 ** disable the use of SQL functions inside views and triggers and in 5833 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5834 ** [expression indexes], [partial indexes], and [generated columns] unless 5835 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5836 ** are innocuous. Developers are advised to avoid using the 5837 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5838 ** function has been carefully audited and found to be free of potentially 5839 ** security-adverse side-effects and information-leaks. 5840 ** </dd> 5841 ** 5842 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5843 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call 5844 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5845 ** This flag instructs SQLite to omit some corner-case optimizations that 5846 ** might disrupt the operation of the [sqlite3_value_subtype()] function, 5847 ** causing it to return zero rather than the correct subtype(). 5848 ** All SQL functions that invoke [sqlite3_value_subtype()] should have this 5849 ** property. If the SQLITE_SUBTYPE property is omitted, then the return 5850 ** value from [sqlite3_value_subtype()] might sometimes be zero even though 5851 ** a non-zero subtype was specified by the function argument expression. 5852 ** 5853 ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd> 5854 ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call 5855 ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its 5856 ** result. 5857 ** Every function that invokes [sqlite3_result_subtype()] should have this 5858 ** property. If it does not, then the call to [sqlite3_result_subtype()] 5859 ** might become a no-op if the function is used as a term in an 5860 ** [expression index]. On the other hand, SQL functions that never invoke 5861 ** [sqlite3_result_subtype()] should avoid setting this property, as the 5862 ** purpose of this property is to disable certain optimizations that are 5863 ** incompatible with subtypes. 5864 ** 5865 ** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd> 5866 ** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate 5867 ** that internally orders the values provided to the first argument. The 5868 ** ordered-set aggregate SQL notation with a single ORDER BY term can be 5869 ** used to invoke this function. If the ordered-set aggregate notation is 5870 ** used on a function that lacks this flag, then an error is raised. Note 5871 ** that the ordered-set aggregate syntax is only available if SQLite is 5872 ** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option. 5873 ** </dd> 5874 ** </dl> 5875 */ 5876 #define SQLITE_DETERMINISTIC 0x000000800 5877 #define SQLITE_DIRECTONLY 0x000080000 5878 #define SQLITE_SUBTYPE 0x000100000 5879 #define SQLITE_INNOCUOUS 0x000200000 5880 #define SQLITE_RESULT_SUBTYPE 0x001000000 5881 #define SQLITE_SELFORDER1 0x002000000 5882 5883 /* 5884 ** CAPI3REF: Deprecated Functions 5885 ** DEPRECATED 5886 ** 5887 ** These functions are [deprecated]. In order to maintain 5888 ** backwards compatibility with older code, these functions continue 5889 ** to be supported. However, new applications should avoid 5890 ** the use of these functions. To encourage programmers to avoid 5891 ** these functions, we will not explain what they do. 5892 */ 5893 #ifndef SQLITE_OMIT_DEPRECATED 5894 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5895 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5896 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5897 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5898 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5899 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5900 void*,sqlite3_int64); 5901 #endif 5902 5903 /* 5904 ** CAPI3REF: Obtaining SQL Values 5905 ** METHOD: sqlite3_value 5906 ** 5907 ** <b>Summary:</b> 5908 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5909 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5910 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5911 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5912 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5913 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5914 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5915 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5916 ** the native byteorder 5917 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5918 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5919 ** <tr><td> <td> <td> 5920 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5921 ** or a UTF-8 TEXT in bytes 5922 ** <tr><td><b>sqlite3_value_bytes16 </b> 5923 ** <td>→ <td>Size of UTF-16 5924 ** TEXT in bytes 5925 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5926 ** datatype of the value 5927 ** <tr><td><b>sqlite3_value_numeric_type </b> 5928 ** <td>→ <td>Best numeric datatype of the value 5929 ** <tr><td><b>sqlite3_value_nochange </b> 5930 ** <td>→ <td>True if the column is unchanged in an UPDATE 5931 ** against a virtual table. 5932 ** <tr><td><b>sqlite3_value_frombind </b> 5933 ** <td>→ <td>True if value originated from a [bound parameter] 5934 ** </table></blockquote> 5935 ** 5936 ** <b>Details:</b> 5937 ** 5938 ** These routines extract type, size, and content information from 5939 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5940 ** are used to pass parameter information into the functions that 5941 ** implement [application-defined SQL functions] and [virtual tables]. 5942 ** 5943 ** These routines work only with [protected sqlite3_value] objects. 5944 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5945 ** is not threadsafe. 5946 ** 5947 ** ^These routines work just like the corresponding [column access functions] 5948 ** except that these routines take a single [protected sqlite3_value] object 5949 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5950 ** 5951 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5952 ** in the native byte-order of the host machine. ^The 5953 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5954 ** extract UTF-16 strings as big-endian and little-endian respectively. 5955 ** 5956 ** ^If [sqlite3_value] object V was initialized 5957 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5958 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5959 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5960 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5961 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5962 ** 5963 ** ^(The sqlite3_value_type(V) interface returns the 5964 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5965 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5966 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5967 ** Other interfaces might change the datatype for an sqlite3_value object. 5968 ** For example, if the datatype is initially SQLITE_INTEGER and 5969 ** sqlite3_value_text(V) is called to extract a text value for that 5970 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5971 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5972 ** occurs is undefined and may change from one release of SQLite to the next. 5973 ** 5974 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5975 ** numeric affinity to the value. This means that an attempt is 5976 ** made to convert the value to an integer or floating point. If 5977 ** such a conversion is possible without loss of information (in other 5978 ** words, if the value is a string that looks like a number) 5979 ** then the conversion is performed. Otherwise no conversion occurs. 5980 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5981 ** 5982 ** ^Within the [xUpdate] method of a [virtual table], the 5983 ** sqlite3_value_nochange(X) interface returns true if and only if 5984 ** the column corresponding to X is unchanged by the UPDATE operation 5985 ** that the xUpdate method call was invoked to implement and if 5986 ** the prior [xColumn] method call that was invoked to extract 5987 ** the value for that column returned without setting a result (probably 5988 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5989 ** was unchanging). ^Within an [xUpdate] method, any value for which 5990 ** sqlite3_value_nochange(X) is true will in all other respects appear 5991 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5992 ** than within an [xUpdate] method call for an UPDATE statement, then 5993 ** the return value is arbitrary and meaningless. 5994 ** 5995 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5996 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5997 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5998 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5999 ** 6000 ** Please pay particular attention to the fact that the pointer returned 6001 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 6002 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 6003 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 6004 ** or [sqlite3_value_text16()]. 6005 ** 6006 ** These routines must be called from the same thread as 6007 ** the SQL function that supplied the [sqlite3_value*] parameters. 6008 ** 6009 ** As long as the input parameter is correct, these routines can only 6010 ** fail if an out-of-memory error occurs during a format conversion. 6011 ** Only the following subset of interfaces are subject to out-of-memory 6012 ** errors: 6013 ** 6014 ** <ul> 6015 ** <li> sqlite3_value_blob() 6016 ** <li> sqlite3_value_text() 6017 ** <li> sqlite3_value_text16() 6018 ** <li> sqlite3_value_text16le() 6019 ** <li> sqlite3_value_text16be() 6020 ** <li> sqlite3_value_bytes() 6021 ** <li> sqlite3_value_bytes16() 6022 ** </ul> 6023 ** 6024 ** If an out-of-memory error occurs, then the return value from these 6025 ** routines is the same as if the column had contained an SQL NULL value. 6026 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 6027 ** by invoking the [sqlite3_errcode()] immediately after the suspect 6028 ** return value is obtained and before any 6029 ** other SQLite interface is called on the same [database connection]. 6030 */ 6031 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 6032 SQLITE_API double sqlite3_value_double(sqlite3_value*); 6033 SQLITE_API int sqlite3_value_int(sqlite3_value*); 6034 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 6035 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 6036 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 6037 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 6038 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 6039 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 6040 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 6041 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 6042 SQLITE_API int sqlite3_value_type(sqlite3_value*); 6043 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 6044 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 6045 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 6046 6047 /* 6048 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object 6049 ** METHOD: sqlite3_value 6050 ** 6051 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 6052 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding 6053 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 6054 ** returns something other than SQLITE_TEXT, then the return value from 6055 ** sqlite3_value_encoding(X) is meaningless. ^Calls to 6056 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)], 6057 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or 6058 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and 6059 ** thus change the return from subsequent calls to sqlite3_value_encoding(X). 6060 ** 6061 ** This routine is intended for used by applications that test and validate 6062 ** the SQLite implementation. This routine is inquiring about the opaque 6063 ** internal state of an [sqlite3_value] object. Ordinary applications should 6064 ** not need to know what the internal state of an sqlite3_value object is and 6065 ** hence should not need to use this interface. 6066 */ 6067 SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 6068 6069 /* 6070 ** CAPI3REF: Finding The Subtype Of SQL Values 6071 ** METHOD: sqlite3_value 6072 ** 6073 ** The sqlite3_value_subtype(V) function returns the subtype for 6074 ** an [application-defined SQL function] argument V. The subtype 6075 ** information can be used to pass a limited amount of context from 6076 ** one SQL function to another. Use the [sqlite3_result_subtype()] 6077 ** routine to set the subtype for the return value of an SQL function. 6078 ** 6079 ** Every [application-defined SQL function] that invokes this interface 6080 ** should include the [SQLITE_SUBTYPE] property in the text 6081 ** encoding argument when the function is [sqlite3_create_function|registered]. 6082 ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype() 6083 ** might return zero instead of the upstream subtype in some corner cases. 6084 */ 6085 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 6086 6087 /* 6088 ** CAPI3REF: Copy And Free SQL Values 6089 ** METHOD: sqlite3_value 6090 ** 6091 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 6092 ** object V and returns a pointer to that copy. ^The [sqlite3_value] returned 6093 ** is a [protected sqlite3_value] object even if the input is not. 6094 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 6095 ** memory allocation fails. ^If V is a [pointer value], then the result 6096 ** of sqlite3_value_dup(V) is a NULL value. 6097 ** 6098 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 6099 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 6100 ** then sqlite3_value_free(V) is a harmless no-op. 6101 */ 6102 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 6103 SQLITE_API void sqlite3_value_free(sqlite3_value*); 6104 6105 /* 6106 ** CAPI3REF: Obtain Aggregate Function Context 6107 ** METHOD: sqlite3_context 6108 ** 6109 ** Implementations of aggregate SQL functions use this 6110 ** routine to allocate memory for storing their state. 6111 ** 6112 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 6113 ** for a particular aggregate function, SQLite allocates 6114 ** N bytes of memory, zeroes out that memory, and returns a pointer 6115 ** to the new memory. ^On second and subsequent calls to 6116 ** sqlite3_aggregate_context() for the same aggregate function instance, 6117 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 6118 ** called once for each invocation of the xStep callback and then one 6119 ** last time when the xFinal callback is invoked. ^(When no rows match 6120 ** an aggregate query, the xStep() callback of the aggregate function 6121 ** implementation is never called and xFinal() is called exactly once. 6122 ** In those cases, sqlite3_aggregate_context() might be called for the 6123 ** first time from within xFinal().)^ 6124 ** 6125 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 6126 ** when first called if N is less than or equal to zero or if a memory 6127 ** allocation error occurs. 6128 ** 6129 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 6130 ** determined by the N parameter on the first successful call. Changing the 6131 ** value of N in any subsequent call to sqlite3_aggregate_context() within 6132 ** the same aggregate function instance will not resize the memory 6133 ** allocation.)^ Within the xFinal callback, it is customary to set 6134 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 6135 ** pointless memory allocations occur. 6136 ** 6137 ** ^SQLite automatically frees the memory allocated by 6138 ** sqlite3_aggregate_context() when the aggregate query concludes. 6139 ** 6140 ** The first parameter must be a copy of the 6141 ** [sqlite3_context | SQL function context] that is the first parameter 6142 ** to the xStep or xFinal callback routine that implements the aggregate 6143 ** function. 6144 ** 6145 ** This routine must be called from the same thread in which 6146 ** the aggregate SQL function is running. 6147 */ 6148 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 6149 6150 /* 6151 ** CAPI3REF: User Data For Functions 6152 ** METHOD: sqlite3_context 6153 ** 6154 ** ^The sqlite3_user_data() interface returns a copy of 6155 ** the pointer that was the pUserData parameter (the 5th parameter) 6156 ** of the [sqlite3_create_function()] 6157 ** and [sqlite3_create_function16()] routines that originally 6158 ** registered the application defined function. 6159 ** 6160 ** This routine must be called from the same thread in which 6161 ** the application-defined function is running. 6162 */ 6163 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 6164 6165 /* 6166 ** CAPI3REF: Database Connection For Functions 6167 ** METHOD: sqlite3_context 6168 ** 6169 ** ^The sqlite3_context_db_handle() interface returns a copy of 6170 ** the pointer to the [database connection] (the 1st parameter) 6171 ** of the [sqlite3_create_function()] 6172 ** and [sqlite3_create_function16()] routines that originally 6173 ** registered the application defined function. 6174 */ 6175 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 6176 6177 /* 6178 ** CAPI3REF: Function Auxiliary Data 6179 ** METHOD: sqlite3_context 6180 ** 6181 ** These functions may be used by (non-aggregate) SQL functions to 6182 ** associate auxiliary data with argument values. If the same argument 6183 ** value is passed to multiple invocations of the same SQL function during 6184 ** query execution, under some circumstances the associated auxiliary data 6185 ** might be preserved. An example of where this might be useful is in a 6186 ** regular-expression matching function. The compiled version of the regular 6187 ** expression can be stored as auxiliary data associated with the pattern string. 6188 ** Then as long as the pattern string remains the same, 6189 ** the compiled regular expression can be reused on multiple 6190 ** invocations of the same function. 6191 ** 6192 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data 6193 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 6194 ** value to the application-defined function. ^N is zero for the left-most 6195 ** function argument. ^If there is no auxiliary data 6196 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 6197 ** returns a NULL pointer. 6198 ** 6199 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the 6200 ** N-th argument of the application-defined function. ^Subsequent 6201 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 6202 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or 6203 ** NULL if the auxiliary data has been discarded. 6204 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 6205 ** SQLite will invoke the destructor function X with parameter P exactly 6206 ** once, when the auxiliary data is discarded. 6207 ** SQLite is free to discard the auxiliary data at any time, including: <ul> 6208 ** <li> ^(when the corresponding function parameter changes)^, or 6209 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 6210 ** SQL statement)^, or 6211 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 6212 ** parameter)^, or 6213 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 6214 ** allocation error occurs.)^ 6215 ** <li> ^(during the original sqlite3_set_auxdata() call if the function 6216 ** is evaluated during query planning instead of during query execution, 6217 ** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul> 6218 ** 6219 ** Note the last two bullets in particular. The destructor X in 6220 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 6221 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 6222 ** should be called near the end of the function implementation and the 6223 ** function implementation should not make any use of P after 6224 ** sqlite3_set_auxdata() has been called. Furthermore, a call to 6225 ** sqlite3_get_auxdata() that occurs immediately after a corresponding call 6226 ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory 6227 ** condition occurred during the sqlite3_set_auxdata() call or if the 6228 ** function is being evaluated during query planning rather than during 6229 ** query execution. 6230 ** 6231 ** ^(In practice, auxiliary data is preserved between function calls for 6232 ** function parameters that are compile-time constants, including literal 6233 ** values and [parameters] and expressions composed from the same.)^ 6234 ** 6235 ** The value of the N parameter to these interfaces should be non-negative. 6236 ** Future enhancements may make use of negative N values to define new 6237 ** kinds of function caching behavior. 6238 ** 6239 ** These routines must be called from the same thread in which 6240 ** the SQL function is running. 6241 ** 6242 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()]. 6243 */ 6244 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 6245 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 6246 6247 /* 6248 ** CAPI3REF: Database Connection Client Data 6249 ** METHOD: sqlite3 6250 ** 6251 ** These functions are used to associate one or more named pointers 6252 ** with a [database connection]. 6253 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P 6254 ** to be attached to [database connection] D using name N. Subsequent 6255 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P 6256 ** or a NULL pointer if there were no prior calls to 6257 ** sqlite3_set_clientdata() with the same values of D and N. 6258 ** Names are compared using strcmp() and are thus case sensitive. 6259 ** It returns 0 on success and SQLITE_NOMEM on allocation failure. 6260 ** 6261 ** If P and X are both non-NULL, then the destructor X is invoked with 6262 ** argument P on the first of the following occurrences: 6263 ** <ul> 6264 ** <li> An out-of-memory error occurs during the call to 6265 ** sqlite3_set_clientdata() which attempts to register pointer P. 6266 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made 6267 ** with the same D and N parameters. 6268 ** <li> The database connection closes. SQLite does not make any guarantees 6269 ** about the order in which destructors are called, only that all 6270 ** destructors will be called exactly once at some point during the 6271 ** database connection closing process. 6272 ** </ul> 6273 ** 6274 ** SQLite does not do anything with client data other than invoke 6275 ** destructors on the client data at the appropriate time. The intended 6276 ** use for client data is to provide a mechanism for wrapper libraries 6277 ** to store additional information about an SQLite database connection. 6278 ** 6279 ** There is no limit (other than available memory) on the number of different 6280 ** client data pointers (with different names) that can be attached to a 6281 ** single database connection. However, the implementation is optimized 6282 ** for the case of having only one or two different client data names. 6283 ** Applications and wrapper libraries are discouraged from using more than 6284 ** one client data name each. 6285 ** 6286 ** There is no way to enumerate the client data pointers 6287 ** associated with a database connection. The N parameter can be thought 6288 ** of as a secret key such that only code that knows the secret key is able 6289 ** to access the associated data. 6290 ** 6291 ** Security Warning: These interfaces should not be exposed in scripting 6292 ** languages or in other circumstances where it might be possible for an 6293 ** attacker to invoke them. Any agent that can invoke these interfaces 6294 ** can probably also take control of the process. 6295 ** 6296 ** Database connection client data is only available for SQLite 6297 ** version 3.44.0 ([dateof:3.44.0]) and later. 6298 ** 6299 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()]. 6300 */ 6301 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*); 6302 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*)); 6303 6304 /* 6305 ** CAPI3REF: Constants Defining Special Destructor Behavior 6306 ** 6307 ** These are special values for the destructor that is passed in as the 6308 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 6309 ** argument is SQLITE_STATIC, it means that the content pointer is constant 6310 ** and will never change. It does not need to be destroyed. ^The 6311 ** SQLITE_TRANSIENT value means that the content will likely change in 6312 ** the near future and that SQLite should make its own private copy of 6313 ** the content before returning. 6314 ** 6315 ** The typedef is necessary to work around problems in certain 6316 ** C++ compilers. 6317 */ 6318 typedef void (*sqlite3_destructor_type)(void*); 6319 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 6320 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 6321 6322 /* 6323 ** CAPI3REF: Setting The Result Of An SQL Function 6324 ** METHOD: sqlite3_context 6325 ** 6326 ** These routines are used by the xFunc or xFinal callbacks that 6327 ** implement SQL functions and aggregates. See 6328 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 6329 ** for additional information. 6330 ** 6331 ** These functions work very much like the [parameter binding] family of 6332 ** functions used to bind values to host parameters in prepared statements. 6333 ** Refer to the [SQL parameter] documentation for additional information. 6334 ** 6335 ** ^The sqlite3_result_blob() interface sets the result from 6336 ** an application-defined function to be the BLOB whose content is pointed 6337 ** to by the second parameter and which is N bytes long where N is the 6338 ** third parameter. 6339 ** 6340 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 6341 ** interfaces set the result of the application-defined function to be 6342 ** a BLOB containing all zero bytes and N bytes in size. 6343 ** 6344 ** ^The sqlite3_result_double() interface sets the result from 6345 ** an application-defined function to be a floating point value specified 6346 ** by its 2nd argument. 6347 ** 6348 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 6349 ** cause the implemented SQL function to throw an exception. 6350 ** ^SQLite uses the string pointed to by the 6351 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 6352 ** as the text of an error message. ^SQLite interprets the error 6353 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 6354 ** interprets the string from sqlite3_result_error16() as UTF-16 using 6355 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 6356 ** ^If the third parameter to sqlite3_result_error() 6357 ** or sqlite3_result_error16() is negative then SQLite takes as the error 6358 ** message all text up through the first zero character. 6359 ** ^If the third parameter to sqlite3_result_error() or 6360 ** sqlite3_result_error16() is non-negative then SQLite takes that many 6361 ** bytes (not characters) from the 2nd parameter as the error message. 6362 ** ^The sqlite3_result_error() and sqlite3_result_error16() 6363 ** routines make a private copy of the error message text before 6364 ** they return. Hence, the calling function can deallocate or 6365 ** modify the text after they return without harm. 6366 ** ^The sqlite3_result_error_code() function changes the error code 6367 ** returned by SQLite as a result of an error in a function. ^By default, 6368 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 6369 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 6370 ** 6371 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 6372 ** error indicating that a string or BLOB is too long to represent. 6373 ** 6374 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 6375 ** error indicating that a memory allocation failed. 6376 ** 6377 ** ^The sqlite3_result_int() interface sets the return value 6378 ** of the application-defined function to be the 32-bit signed integer 6379 ** value given in the 2nd argument. 6380 ** ^The sqlite3_result_int64() interface sets the return value 6381 ** of the application-defined function to be the 64-bit signed integer 6382 ** value given in the 2nd argument. 6383 ** 6384 ** ^The sqlite3_result_null() interface sets the return value 6385 ** of the application-defined function to be NULL. 6386 ** 6387 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 6388 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 6389 ** set the return value of the application-defined function to be 6390 ** a text string which is represented as UTF-8, UTF-16 native byte order, 6391 ** UTF-16 little endian, or UTF-16 big endian, respectively. 6392 ** ^The sqlite3_result_text64() interface sets the return value of an 6393 ** application-defined function to be a text string in an encoding 6394 ** specified by the fifth (and last) parameter, which must be one 6395 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 6396 ** ^SQLite takes the text result from the application from 6397 ** the 2nd parameter of the sqlite3_result_text* interfaces. 6398 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 6399 ** other than sqlite3_result_text64() is negative, then SQLite computes 6400 ** the string length itself by searching the 2nd parameter for the first 6401 ** zero character. 6402 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 6403 ** is non-negative, then as many bytes (not characters) of the text 6404 ** pointed to by the 2nd parameter are taken as the application-defined 6405 ** function result. If the 3rd parameter is non-negative, then it 6406 ** must be the byte offset into the string where the NUL terminator would 6407 ** appear if the string were NUL terminated. If any NUL characters occur 6408 ** in the string at a byte offset that is less than the value of the 3rd 6409 ** parameter, then the resulting string will contain embedded NULs and the 6410 ** result of expressions operating on strings with embedded NULs is undefined. 6411 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6412 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 6413 ** function as the destructor on the text or BLOB result when it has 6414 ** finished using that result. 6415 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 6416 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 6417 ** assumes that the text or BLOB result is in constant space and does not 6418 ** copy the content of the parameter nor call a destructor on the content 6419 ** when it has finished using that result. 6420 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6421 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 6422 ** then SQLite makes a copy of the result into space obtained 6423 ** from [sqlite3_malloc()] before it returns. 6424 ** 6425 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 6426 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 6427 ** when the encoding is not UTF8, if the input UTF16 begins with a 6428 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 6429 ** string and the rest of the string is interpreted according to the 6430 ** byte-order specified by the BOM. ^The byte-order specified by 6431 ** the BOM at the beginning of the text overrides the byte-order 6432 ** specified by the interface procedure. ^So, for example, if 6433 ** sqlite3_result_text16le() is invoked with text that begins 6434 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 6435 ** first two bytes of input are skipped and the remaining input 6436 ** is interpreted as UTF16BE text. 6437 ** 6438 ** ^For UTF16 input text to the sqlite3_result_text16(), 6439 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 6440 ** sqlite3_result_text64() routines, if the text contains invalid 6441 ** UTF16 characters, the invalid characters might be converted 6442 ** into the unicode replacement character, U+FFFD. 6443 ** 6444 ** ^The sqlite3_result_value() interface sets the result of 6445 ** the application-defined function to be a copy of the 6446 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 6447 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 6448 ** so that the [sqlite3_value] specified in the parameter may change or 6449 ** be deallocated after sqlite3_result_value() returns without harm. 6450 ** ^A [protected sqlite3_value] object may always be used where an 6451 ** [unprotected sqlite3_value] object is required, so either 6452 ** kind of [sqlite3_value] object can be used with this interface. 6453 ** 6454 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 6455 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 6456 ** also associates the host-language pointer P or type T with that 6457 ** NULL value such that the pointer can be retrieved within an 6458 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 6459 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 6460 ** for the P parameter. ^SQLite invokes D with P as its only argument 6461 ** when SQLite is finished with P. The T parameter should be a static 6462 ** string and preferably a string literal. The sqlite3_result_pointer() 6463 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 6464 ** 6465 ** If these routines are called from within a different thread 6466 ** than the one containing the application-defined function that received 6467 ** the [sqlite3_context] pointer, the results are undefined. 6468 */ 6469 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 6470 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 6471 sqlite3_uint64,void(*)(void*)); 6472 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 6473 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 6474 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 6475 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 6476 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 6477 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 6478 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 6479 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 6480 SQLITE_API void sqlite3_result_null(sqlite3_context*); 6481 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 6482 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 6483 void(*)(void*), unsigned char encoding); 6484 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 6485 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 6486 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 6487 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 6488 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 6489 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 6490 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 6491 6492 6493 /* 6494 ** CAPI3REF: Setting The Subtype Of An SQL Function 6495 ** METHOD: sqlite3_context 6496 ** 6497 ** The sqlite3_result_subtype(C,T) function causes the subtype of 6498 ** the result from the [application-defined SQL function] with 6499 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 6500 ** of the subtype T are preserved in current versions of SQLite; 6501 ** higher order bits are discarded. 6502 ** The number of subtype bytes preserved by SQLite might increase 6503 ** in future releases of SQLite. 6504 ** 6505 ** Every [application-defined SQL function] that invokes this interface 6506 ** should include the [SQLITE_RESULT_SUBTYPE] property in its 6507 ** text encoding argument when the SQL function is 6508 ** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE] 6509 ** property is omitted from the function that invokes sqlite3_result_subtype(), 6510 ** then in some cases the sqlite3_result_subtype() might fail to set 6511 ** the result subtype. 6512 ** 6513 ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any 6514 ** SQL function that invokes the sqlite3_result_subtype() interface 6515 ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise 6516 ** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1 6517 ** by default. 6518 */ 6519 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 6520 6521 /* 6522 ** CAPI3REF: Define New Collating Sequences 6523 ** METHOD: sqlite3 6524 ** 6525 ** ^These functions add, remove, or modify a [collation] associated 6526 ** with the [database connection] specified as the first argument. 6527 ** 6528 ** ^The name of the collation is a UTF-8 string 6529 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 6530 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 6531 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 6532 ** considered to be the same name. 6533 ** 6534 ** ^(The third argument (eTextRep) must be one of the constants: 6535 ** <ul> 6536 ** <li> [SQLITE_UTF8], 6537 ** <li> [SQLITE_UTF16LE], 6538 ** <li> [SQLITE_UTF16BE], 6539 ** <li> [SQLITE_UTF16], or 6540 ** <li> [SQLITE_UTF16_ALIGNED]. 6541 ** </ul>)^ 6542 ** ^The eTextRep argument determines the encoding of strings passed 6543 ** to the collating function callback, xCompare. 6544 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6545 ** force strings to be UTF16 with native byte order. 6546 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6547 ** on an even byte address. 6548 ** 6549 ** ^The fourth argument, pArg, is an application data pointer that is passed 6550 ** through as the first argument to the collating function callback. 6551 ** 6552 ** ^The fifth argument, xCompare, is a pointer to the collating function. 6553 ** ^Multiple collating functions can be registered using the same name but 6554 ** with different eTextRep parameters and SQLite will use whichever 6555 ** function requires the least amount of data transformation. 6556 ** ^If the xCompare argument is NULL then the collating function is 6557 ** deleted. ^When all collating functions having the same name are deleted, 6558 ** that collation is no longer usable. 6559 ** 6560 ** ^The collating function callback is invoked with a copy of the pArg 6561 ** application data pointer and with two strings in the encoding specified 6562 ** by the eTextRep argument. The two integer parameters to the collating 6563 ** function callback are the length of the two strings, in bytes. The collating 6564 ** function must return an integer that is negative, zero, or positive 6565 ** if the first string is less than, equal to, or greater than the second, 6566 ** respectively. A collating function must always return the same answer 6567 ** given the same inputs. If two or more collating functions are registered 6568 ** to the same collation name (using different eTextRep values) then all 6569 ** must give an equivalent answer when invoked with equivalent strings. 6570 ** The collating function must obey the following properties for all 6571 ** strings A, B, and C: 6572 ** 6573 ** <ol> 6574 ** <li> If A==B then B==A. 6575 ** <li> If A==B and B==C then A==C. 6576 ** <li> If A<B THEN B>A. 6577 ** <li> If A<B and B<C then A<C. 6578 ** </ol> 6579 ** 6580 ** If a collating function fails any of the above constraints and that 6581 ** collating function is registered and used, then the behavior of SQLite 6582 ** is undefined. 6583 ** 6584 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6585 ** with the addition that the xDestroy callback is invoked on pArg when 6586 ** the collating function is deleted. 6587 ** ^Collating functions are deleted when they are overridden by later 6588 ** calls to the collation creation functions or when the 6589 ** [database connection] is closed using [sqlite3_close()]. 6590 ** 6591 ** ^The xDestroy callback is <u>not</u> called if the 6592 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6593 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6594 ** check the return code and dispose of the application data pointer 6595 ** themselves rather than expecting SQLite to deal with it for them. 6596 ** This is different from every other SQLite interface. The inconsistency 6597 ** is unfortunate but cannot be changed without breaking backwards 6598 ** compatibility. 6599 ** 6600 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6601 */ 6602 SQLITE_API int sqlite3_create_collation( 6603 sqlite3*, 6604 const char *zName, 6605 int eTextRep, 6606 void *pArg, 6607 int(*xCompare)(void*,int,const void*,int,const void*) 6608 ); 6609 SQLITE_API int sqlite3_create_collation_v2( 6610 sqlite3*, 6611 const char *zName, 6612 int eTextRep, 6613 void *pArg, 6614 int(*xCompare)(void*,int,const void*,int,const void*), 6615 void(*xDestroy)(void*) 6616 ); 6617 SQLITE_API int sqlite3_create_collation16( 6618 sqlite3*, 6619 const void *zName, 6620 int eTextRep, 6621 void *pArg, 6622 int(*xCompare)(void*,int,const void*,int,const void*) 6623 ); 6624 6625 /* 6626 ** CAPI3REF: Collation Needed Callbacks 6627 ** METHOD: sqlite3 6628 ** 6629 ** ^To avoid having to register all collation sequences before a database 6630 ** can be used, a single callback function may be registered with the 6631 ** [database connection] to be invoked whenever an undefined collation 6632 ** sequence is required. 6633 ** 6634 ** ^If the function is registered using the sqlite3_collation_needed() API, 6635 ** then it is passed the names of undefined collation sequences as strings 6636 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6637 ** the names are passed as UTF-16 in machine native byte order. 6638 ** ^A call to either function replaces the existing collation-needed callback. 6639 ** 6640 ** ^(When the callback is invoked, the first argument passed is a copy 6641 ** of the second argument to sqlite3_collation_needed() or 6642 ** sqlite3_collation_needed16(). The second argument is the database 6643 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6644 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6645 ** sequence function required. The fourth parameter is the name of the 6646 ** required collation sequence.)^ 6647 ** 6648 ** The callback function should register the desired collation using 6649 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6650 ** [sqlite3_create_collation_v2()]. 6651 */ 6652 SQLITE_API int sqlite3_collation_needed( 6653 sqlite3*, 6654 void*, 6655 void(*)(void*,sqlite3*,int eTextRep,const char*) 6656 ); 6657 SQLITE_API int sqlite3_collation_needed16( 6658 sqlite3*, 6659 void*, 6660 void(*)(void*,sqlite3*,int eTextRep,const void*) 6661 ); 6662 6663 #ifdef SQLITE_ENABLE_CEROD 6664 /* 6665 ** Specify the activation key for a CEROD database. Unless 6666 ** activated, none of the CEROD routines will work. 6667 */ 6668 SQLITE_API void sqlite3_activate_cerod( 6669 const char *zPassPhrase /* Activation phrase */ 6670 ); 6671 #endif 6672 6673 /* 6674 ** CAPI3REF: Suspend Execution For A Short Time 6675 ** 6676 ** The sqlite3_sleep() function causes the current thread to suspend execution 6677 ** for at least a number of milliseconds specified in its parameter. 6678 ** 6679 ** If the operating system does not support sleep requests with 6680 ** millisecond time resolution, then the time will be rounded up to 6681 ** the nearest second. The number of milliseconds of sleep actually 6682 ** requested from the operating system is returned. 6683 ** 6684 ** ^SQLite implements this interface by calling the xSleep() 6685 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6686 ** of the default VFS is not implemented correctly, or not implemented at 6687 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6688 ** in the previous paragraphs. 6689 ** 6690 ** If a negative argument is passed to sqlite3_sleep() the results vary by 6691 ** VFS and operating system. Some system treat a negative argument as an 6692 ** instruction to sleep forever. Others understand it to mean do not sleep 6693 ** at all. ^In SQLite version 3.42.0 and later, a negative 6694 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed 6695 ** down into the xSleep method of the VFS. 6696 */ 6697 SQLITE_API int sqlite3_sleep(int); 6698 6699 /* 6700 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6701 ** 6702 ** ^(If this global variable is made to point to a string which is 6703 ** the name of a folder (a.k.a. directory), then all temporary files 6704 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6705 ** will be placed in that directory.)^ ^If this variable 6706 ** is a NULL pointer, then SQLite performs a search for an appropriate 6707 ** temporary file directory. 6708 ** 6709 ** Applications are strongly discouraged from using this global variable. 6710 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6711 ** But for all other platforms, it is highly recommended that applications 6712 ** neither read nor write this variable. This global variable is a relic 6713 ** that exists for backwards compatibility of legacy applications and should 6714 ** be avoided in new projects. 6715 ** 6716 ** It is not safe to read or modify this variable in more than one 6717 ** thread at a time. It is not safe to read or modify this variable 6718 ** if a [database connection] is being used at the same time in a separate 6719 ** thread. 6720 ** It is intended that this variable be set once 6721 ** as part of process initialization and before any SQLite interface 6722 ** routines have been called and that this variable remain unchanged 6723 ** thereafter. 6724 ** 6725 ** ^The [temp_store_directory pragma] may modify this variable and cause 6726 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6727 ** the [temp_store_directory pragma] always assumes that any string 6728 ** that this variable points to is held in memory obtained from 6729 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6730 ** using [sqlite3_free]. 6731 ** Hence, if this variable is modified directly, either it should be 6732 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6733 ** or else the use of the [temp_store_directory pragma] should be avoided. 6734 ** Except when requested by the [temp_store_directory pragma], SQLite 6735 ** does not free the memory that sqlite3_temp_directory points to. If 6736 ** the application wants that memory to be freed, it must do 6737 ** so itself, taking care to only do so after all [database connection] 6738 ** objects have been destroyed. 6739 ** 6740 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6741 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6742 ** features that require the use of temporary files may fail. Here is an 6743 ** example of how to do this using C++ with the Windows Runtime: 6744 ** 6745 ** <blockquote><pre> 6746 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6747 ** TemporaryFolder->Path->Data(); 6748 ** char zPathBuf[MAX_PATH + 1]; 6749 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6750 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6751 ** NULL, NULL); 6752 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6753 ** </pre></blockquote> 6754 */ 6755 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6756 6757 /* 6758 ** CAPI3REF: Name Of The Folder Holding Database Files 6759 ** 6760 ** ^(If this global variable is made to point to a string which is 6761 ** the name of a folder (a.k.a. directory), then all database files 6762 ** specified with a relative pathname and created or accessed by 6763 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6764 ** to be relative to that directory.)^ ^If this variable is a NULL 6765 ** pointer, then SQLite assumes that all database files specified 6766 ** with a relative pathname are relative to the current directory 6767 ** for the process. Only the windows VFS makes use of this global 6768 ** variable; it is ignored by the unix VFS. 6769 ** 6770 ** Changing the value of this variable while a database connection is 6771 ** open can result in a corrupt database. 6772 ** 6773 ** It is not safe to read or modify this variable in more than one 6774 ** thread at a time. It is not safe to read or modify this variable 6775 ** if a [database connection] is being used at the same time in a separate 6776 ** thread. 6777 ** It is intended that this variable be set once 6778 ** as part of process initialization and before any SQLite interface 6779 ** routines have been called and that this variable remain unchanged 6780 ** thereafter. 6781 ** 6782 ** ^The [data_store_directory pragma] may modify this variable and cause 6783 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6784 ** the [data_store_directory pragma] always assumes that any string 6785 ** that this variable points to is held in memory obtained from 6786 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6787 ** using [sqlite3_free]. 6788 ** Hence, if this variable is modified directly, either it should be 6789 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6790 ** or else the use of the [data_store_directory pragma] should be avoided. 6791 */ 6792 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6793 6794 /* 6795 ** CAPI3REF: Win32 Specific Interface 6796 ** 6797 ** These interfaces are available only on Windows. The 6798 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6799 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6800 ** zValue, depending on the value of the type parameter. The zValue parameter 6801 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6802 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6803 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6804 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6805 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6806 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6807 ** the current directory on the sub-platforms of Win32 where that concept is 6808 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6809 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6810 ** sqlite3_win32_set_directory interface except the string parameter must be 6811 ** UTF-8 or UTF-16, respectively. 6812 */ 6813 SQLITE_API int sqlite3_win32_set_directory( 6814 unsigned long type, /* Identifier for directory being set or reset */ 6815 void *zValue /* New value for directory being set or reset */ 6816 ); 6817 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6818 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6819 6820 /* 6821 ** CAPI3REF: Win32 Directory Types 6822 ** 6823 ** These macros are only available on Windows. They define the allowed values 6824 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6825 */ 6826 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6827 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6828 6829 /* 6830 ** CAPI3REF: Test For Auto-Commit Mode 6831 ** KEYWORDS: {autocommit mode} 6832 ** METHOD: sqlite3 6833 ** 6834 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6835 ** zero if the given database connection is or is not in autocommit mode, 6836 ** respectively. ^Autocommit mode is on by default. 6837 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6838 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6839 ** 6840 ** If certain kinds of errors occur on a statement within a multi-statement 6841 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6842 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6843 ** transaction might be rolled back automatically. The only way to 6844 ** find out whether SQLite automatically rolled back the transaction after 6845 ** an error is to use this function. 6846 ** 6847 ** If another thread changes the autocommit status of the database 6848 ** connection while this routine is running, then the return value 6849 ** is undefined. 6850 */ 6851 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6852 6853 /* 6854 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6855 ** METHOD: sqlite3_stmt 6856 ** 6857 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6858 ** to which a [prepared statement] belongs. ^The [database connection] 6859 ** returned by sqlite3_db_handle is the same [database connection] 6860 ** that was the first argument 6861 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6862 ** create the statement in the first place. 6863 */ 6864 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6865 6866 /* 6867 ** CAPI3REF: Return The Schema Name For A Database Connection 6868 ** METHOD: sqlite3 6869 ** 6870 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6871 ** for the N-th database on database connection D, or a NULL pointer if N is 6872 ** out of range. An N value of 0 means the main database file. An N of 1 is 6873 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6874 ** databases. 6875 ** 6876 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6877 ** by SQLite itself. The string might be deallocated by any operation that 6878 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6879 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6880 ** occur on a different thread. Applications that need to 6881 ** remember the string long-term should make their own copy. Applications that 6882 ** are accessing the same database connection simultaneously on multiple 6883 ** threads should mutex-protect calls to this API and should make their own 6884 ** private copy of the result prior to releasing the mutex. 6885 */ 6886 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6887 6888 /* 6889 ** CAPI3REF: Return The Filename For A Database Connection 6890 ** METHOD: sqlite3 6891 ** 6892 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6893 ** associated with database N of connection D. 6894 ** ^If there is no attached database N on the database 6895 ** connection D, or if database N is a temporary or in-memory database, then 6896 ** this function will return either a NULL pointer or an empty string. 6897 ** 6898 ** ^The string value returned by this routine is owned and managed by 6899 ** the database connection. ^The value will be valid until the database N 6900 ** is [DETACH]-ed or until the database connection closes. 6901 ** 6902 ** ^The filename returned by this function is the output of the 6903 ** xFullPathname method of the [VFS]. ^In other words, the filename 6904 ** will be an absolute pathname, even if the filename used 6905 ** to open the database originally was a URI or relative pathname. 6906 ** 6907 ** If the filename pointer returned by this routine is not NULL, then it 6908 ** can be used as the filename input parameter to these routines: 6909 ** <ul> 6910 ** <li> [sqlite3_uri_parameter()] 6911 ** <li> [sqlite3_uri_boolean()] 6912 ** <li> [sqlite3_uri_int64()] 6913 ** <li> [sqlite3_filename_database()] 6914 ** <li> [sqlite3_filename_journal()] 6915 ** <li> [sqlite3_filename_wal()] 6916 ** </ul> 6917 */ 6918 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6919 6920 /* 6921 ** CAPI3REF: Determine if a database is read-only 6922 ** METHOD: sqlite3 6923 ** 6924 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6925 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6926 ** the name of a database on connection D. 6927 */ 6928 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6929 6930 /* 6931 ** CAPI3REF: Determine the transaction state of a database 6932 ** METHOD: sqlite3 6933 ** 6934 ** ^The sqlite3_txn_state(D,S) interface returns the current 6935 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6936 ** then the highest transaction state of any schema on database connection D 6937 ** is returned. Transaction states are (in order of lowest to highest): 6938 ** <ol> 6939 ** <li value="0"> SQLITE_TXN_NONE 6940 ** <li value="1"> SQLITE_TXN_READ 6941 ** <li value="2"> SQLITE_TXN_WRITE 6942 ** </ol> 6943 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6944 ** a valid schema, then -1 is returned. 6945 */ 6946 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6947 6948 /* 6949 ** CAPI3REF: Allowed return values from sqlite3_txn_state() 6950 ** KEYWORDS: {transaction state} 6951 ** 6952 ** These constants define the current transaction state of a database file. 6953 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6954 ** constants in order to describe the transaction state of schema S 6955 ** in [database connection] D. 6956 ** 6957 ** <dl> 6958 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6959 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6960 ** pending.</dd> 6961 ** 6962 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6963 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6964 ** in a read transaction. Content has been read from the database file 6965 ** but nothing in the database file has changed. The transaction state 6966 ** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are 6967 ** no other conflicting concurrent write transactions. The transaction 6968 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6969 ** [COMMIT].</dd> 6970 ** 6971 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6972 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6973 ** in a write transaction. Content has been written to the database file 6974 ** but has not yet committed. The transaction state will change to 6975 ** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6976 */ 6977 #define SQLITE_TXN_NONE 0 6978 #define SQLITE_TXN_READ 1 6979 #define SQLITE_TXN_WRITE 2 6980 6981 /* 6982 ** CAPI3REF: Find the next prepared statement 6983 ** METHOD: sqlite3 6984 ** 6985 ** ^This interface returns a pointer to the next [prepared statement] after 6986 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6987 ** then this interface returns a pointer to the first prepared statement 6988 ** associated with the database connection pDb. ^If no prepared statement 6989 ** satisfies the conditions of this routine, it returns NULL. 6990 ** 6991 ** The [database connection] pointer D in a call to 6992 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6993 ** connection and in particular must not be a NULL pointer. 6994 */ 6995 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6996 6997 /* 6998 ** CAPI3REF: Commit And Rollback Notification Callbacks 6999 ** METHOD: sqlite3 7000 ** 7001 ** ^The sqlite3_commit_hook() interface registers a callback 7002 ** function to be invoked whenever a transaction is [COMMIT | committed]. 7003 ** ^Any callback set by a previous call to sqlite3_commit_hook() 7004 ** for the same database connection is overridden. 7005 ** ^The sqlite3_rollback_hook() interface registers a callback 7006 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 7007 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 7008 ** for the same database connection is overridden. 7009 ** ^The pArg argument is passed through to the callback. 7010 ** ^If the callback on a commit hook function returns non-zero, 7011 ** then the commit is converted into a rollback. 7012 ** 7013 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 7014 ** return the P argument from the previous call of the same function 7015 ** on the same [database connection] D, or NULL for 7016 ** the first call for each function on D. 7017 ** 7018 ** The commit and rollback hook callbacks are not reentrant. 7019 ** The callback implementation must not do anything that will modify 7020 ** the database connection that invoked the callback. Any actions 7021 ** to modify the database connection must be deferred until after the 7022 ** completion of the [sqlite3_step()] call that triggered the commit 7023 ** or rollback hook in the first place. 7024 ** Note that running any other SQL statements, including SELECT statements, 7025 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 7026 ** the database connections for the meaning of "modify" in this paragraph. 7027 ** 7028 ** ^Registering a NULL function disables the callback. 7029 ** 7030 ** ^When the commit hook callback routine returns zero, the [COMMIT] 7031 ** operation is allowed to continue normally. ^If the commit hook 7032 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 7033 ** ^The rollback hook is invoked on a rollback that results from a commit 7034 ** hook returning non-zero, just as it would be with any other rollback. 7035 ** 7036 ** ^For the purposes of this API, a transaction is said to have been 7037 ** rolled back if an explicit "ROLLBACK" statement is executed, or 7038 ** an error or constraint causes an implicit rollback to occur. 7039 ** ^The rollback callback is not invoked if a transaction is 7040 ** automatically rolled back because the database connection is closed. 7041 ** 7042 ** See also the [sqlite3_update_hook()] interface. 7043 */ 7044 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 7045 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 7046 7047 /* 7048 ** CAPI3REF: Autovacuum Compaction Amount Callback 7049 ** METHOD: sqlite3 7050 ** 7051 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 7052 ** function C that is invoked prior to each autovacuum of the database 7053 ** file. ^The callback is passed a copy of the generic data pointer (P), 7054 ** the schema-name of the attached database that is being autovacuumed, 7055 ** the size of the database file in pages, the number of free pages, 7056 ** and the number of bytes per page, respectively. The callback should 7057 ** return the number of free pages that should be removed by the 7058 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 7059 ** ^If the value returned is greater than or equal to the number of 7060 ** free pages, then a complete autovacuum happens. 7061 ** 7062 ** <p>^If there are multiple ATTACH-ed database files that are being 7063 ** modified as part of a transaction commit, then the autovacuum pages 7064 ** callback is invoked separately for each file. 7065 ** 7066 ** <p><b>The callback is not reentrant.</b> The callback function should 7067 ** not attempt to invoke any other SQLite interface. If it does, bad 7068 ** things may happen, including segmentation faults and corrupt database 7069 ** files. The callback function should be a simple function that 7070 ** does some arithmetic on its input parameters and returns a result. 7071 ** 7072 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 7073 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 7074 ** invoked whenever the database connection closes or when the callback 7075 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 7076 ** 7077 ** <p>^There is only one autovacuum pages callback per database connection. 7078 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 7079 ** previous invocations for that database connection. ^If the callback 7080 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 7081 ** then the autovacuum steps callback is canceled. The return value 7082 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 7083 ** be some other error code if something goes wrong. The current 7084 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 7085 ** return codes might be added in future releases. 7086 ** 7087 ** <p>If no autovacuum pages callback is specified (the usual case) or 7088 ** a NULL pointer is provided for the callback, 7089 ** then the default behavior is to vacuum all free pages. So, in other 7090 ** words, the default behavior is the same as if the callback function 7091 ** were something like this: 7092 ** 7093 ** <blockquote><pre> 7094 ** unsigned int demonstration_autovac_pages_callback( 7095 ** void *pClientData, 7096 ** const char *zSchema, 7097 ** unsigned int nDbPage, 7098 ** unsigned int nFreePage, 7099 ** unsigned int nBytePerPage 7100 ** ){ 7101 ** return nFreePage; 7102 ** } 7103 ** </pre></blockquote> 7104 */ 7105 SQLITE_API int sqlite3_autovacuum_pages( 7106 sqlite3 *db, 7107 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 7108 void*, 7109 void(*)(void*) 7110 ); 7111 7112 7113 /* 7114 ** CAPI3REF: Data Change Notification Callbacks 7115 ** METHOD: sqlite3 7116 ** 7117 ** ^The sqlite3_update_hook() interface registers a callback function 7118 ** with the [database connection] identified by the first argument 7119 ** to be invoked whenever a row is updated, inserted or deleted in 7120 ** a [rowid table]. 7121 ** ^Any callback set by a previous call to this function 7122 ** for the same database connection is overridden. 7123 ** 7124 ** ^The second argument is a pointer to the function to invoke when a 7125 ** row is updated, inserted or deleted in a rowid table. 7126 ** ^The update hook is disabled by invoking sqlite3_update_hook() 7127 ** with a NULL pointer as the second parameter. 7128 ** ^The first argument to the callback is a copy of the third argument 7129 ** to sqlite3_update_hook(). 7130 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 7131 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 7132 ** to be invoked. 7133 ** ^The third and fourth arguments to the callback contain pointers to the 7134 ** database and table name containing the affected row. 7135 ** ^The final callback parameter is the [rowid] of the row. 7136 ** ^In the case of an update, this is the [rowid] after the update takes place. 7137 ** 7138 ** ^(The update hook is not invoked when internal system tables are 7139 ** modified (i.e. sqlite_sequence).)^ 7140 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 7141 ** 7142 ** ^In the current implementation, the update hook 7143 ** is not invoked when conflicting rows are deleted because of an 7144 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 7145 ** invoked when rows are deleted using the [truncate optimization]. 7146 ** The exceptions defined in this paragraph might change in a future 7147 ** release of SQLite. 7148 ** 7149 ** Whether the update hook is invoked before or after the 7150 ** corresponding change is currently unspecified and may differ 7151 ** depending on the type of change. Do not rely on the order of the 7152 ** hook call with regards to the final result of the operation which 7153 ** triggers the hook. 7154 ** 7155 ** The update hook implementation must not do anything that will modify 7156 ** the database connection that invoked the update hook. Any actions 7157 ** to modify the database connection must be deferred until after the 7158 ** completion of the [sqlite3_step()] call that triggered the update hook. 7159 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 7160 ** database connections for the meaning of "modify" in this paragraph. 7161 ** 7162 ** ^The sqlite3_update_hook(D,C,P) function 7163 ** returns the P argument from the previous call 7164 ** on the same [database connection] D, or NULL for 7165 ** the first call on D. 7166 ** 7167 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 7168 ** and [sqlite3_preupdate_hook()] interfaces. 7169 */ 7170 SQLITE_API void *sqlite3_update_hook( 7171 sqlite3*, 7172 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 7173 void* 7174 ); 7175 7176 /* 7177 ** CAPI3REF: Enable Or Disable Shared Pager Cache 7178 ** 7179 ** ^(This routine enables or disables the sharing of the database cache 7180 ** and schema data structures between [database connection | connections] 7181 ** to the same database. Sharing is enabled if the argument is true 7182 ** and disabled if the argument is false.)^ 7183 ** 7184 ** This interface is omitted if SQLite is compiled with 7185 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 7186 ** compile-time option is recommended because the 7187 ** [use of shared cache mode is discouraged]. 7188 ** 7189 ** ^Cache sharing is enabled and disabled for an entire process. 7190 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 7191 ** In prior versions of SQLite, 7192 ** sharing was enabled or disabled for each thread separately. 7193 ** 7194 ** ^(The cache sharing mode set by this interface effects all subsequent 7195 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 7196 ** Existing database connections continue to use the sharing mode 7197 ** that was in effect at the time they were opened.)^ 7198 ** 7199 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 7200 ** successfully. An [error code] is returned otherwise.)^ 7201 ** 7202 ** ^Shared cache is disabled by default. It is recommended that it stay 7203 ** that way. In other words, do not use this routine. This interface 7204 ** continues to be provided for historical compatibility, but its use is 7205 ** discouraged. Any use of shared cache is discouraged. If shared cache 7206 ** must be used, it is recommended that shared cache only be enabled for 7207 ** individual database connections using the [sqlite3_open_v2()] interface 7208 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 7209 ** 7210 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 7211 ** and will always return SQLITE_MISUSE. On those systems, 7212 ** shared cache mode should be enabled per-database connection via 7213 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 7214 ** 7215 ** This interface is threadsafe on processors where writing a 7216 ** 32-bit integer is atomic. 7217 ** 7218 ** See Also: [SQLite Shared-Cache Mode] 7219 */ 7220 SQLITE_API int sqlite3_enable_shared_cache(int); 7221 7222 /* 7223 ** CAPI3REF: Attempt To Free Heap Memory 7224 ** 7225 ** ^The sqlite3_release_memory() interface attempts to free N bytes 7226 ** of heap memory by deallocating non-essential memory allocations 7227 ** held by the database library. Memory used to cache database 7228 ** pages to improve performance is an example of non-essential memory. 7229 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 7230 ** which might be more or less than the amount requested. 7231 ** ^The sqlite3_release_memory() routine is a no-op returning zero 7232 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 7233 ** 7234 ** See also: [sqlite3_db_release_memory()] 7235 */ 7236 SQLITE_API int sqlite3_release_memory(int); 7237 7238 /* 7239 ** CAPI3REF: Free Memory Used By A Database Connection 7240 ** METHOD: sqlite3 7241 ** 7242 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 7243 ** memory as possible from database connection D. Unlike the 7244 ** [sqlite3_release_memory()] interface, this interface is in effect even 7245 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 7246 ** omitted. 7247 ** 7248 ** See also: [sqlite3_release_memory()] 7249 */ 7250 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 7251 7252 /* 7253 ** CAPI3REF: Impose A Limit On Heap Size 7254 ** 7255 ** These interfaces impose limits on the amount of heap memory that will be 7256 ** used by all database connections within a single process. 7257 ** 7258 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 7259 ** soft limit on the amount of heap memory that may be allocated by SQLite. 7260 ** ^SQLite strives to keep heap memory utilization below the soft heap 7261 ** limit by reducing the number of pages held in the page cache 7262 ** as heap memory usages approaches the limit. 7263 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 7264 ** below the limit, it will exceed the limit rather than generate 7265 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 7266 ** is advisory only. 7267 ** 7268 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 7269 ** N bytes on the amount of memory that will be allocated. ^The 7270 ** sqlite3_hard_heap_limit64(N) interface is similar to 7271 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 7272 ** when the hard heap limit is reached. 7273 ** 7274 ** ^The return value from both sqlite3_soft_heap_limit64() and 7275 ** sqlite3_hard_heap_limit64() is the size of 7276 ** the heap limit prior to the call, or negative in the case of an 7277 ** error. ^If the argument N is negative 7278 ** then no change is made to the heap limit. Hence, the current 7279 ** size of heap limits can be determined by invoking 7280 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 7281 ** 7282 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 7283 ** 7284 ** ^The soft heap limit may not be greater than the hard heap limit. 7285 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 7286 ** is invoked with a value of N that is greater than the hard heap limit, 7287 ** the soft heap limit is set to the value of the hard heap limit. 7288 ** ^The soft heap limit is automatically enabled whenever the hard heap 7289 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 7290 ** the soft heap limit is outside the range of 1..N, then the soft heap 7291 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 7292 ** hard heap limit is enabled makes the soft heap limit equal to the 7293 ** hard heap limit. 7294 ** 7295 ** The memory allocation limits can also be adjusted using 7296 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 7297 ** 7298 ** ^(The heap limits are not enforced in the current implementation 7299 ** if one or more of following conditions are true: 7300 ** 7301 ** <ul> 7302 ** <li> The limit value is set to zero. 7303 ** <li> Memory accounting is disabled using a combination of the 7304 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 7305 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 7306 ** <li> An alternative page cache implementation is specified using 7307 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 7308 ** <li> The page cache allocates from its own memory pool supplied 7309 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 7310 ** from the heap. 7311 ** </ul>)^ 7312 ** 7313 ** The circumstances under which SQLite will enforce the heap limits may 7314 ** change in future releases of SQLite. 7315 */ 7316 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 7317 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 7318 7319 /* 7320 ** CAPI3REF: Deprecated Soft Heap Limit Interface 7321 ** DEPRECATED 7322 ** 7323 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 7324 ** interface. This routine is provided for historical compatibility 7325 ** only. All new applications should use the 7326 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 7327 */ 7328 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 7329 7330 7331 /* 7332 ** CAPI3REF: Extract Metadata About A Column Of A Table 7333 ** METHOD: sqlite3 7334 ** 7335 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 7336 ** information about column C of table T in database D 7337 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 7338 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 7339 ** the final five arguments with appropriate values if the specified 7340 ** column exists. ^The sqlite3_table_column_metadata() interface returns 7341 ** SQLITE_ERROR if the specified column does not exist. 7342 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 7343 ** NULL pointer, then this routine simply checks for the existence of the 7344 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 7345 ** does not. If the table name parameter T in a call to 7346 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 7347 ** undefined behavior. 7348 ** 7349 ** ^The column is identified by the second, third and fourth parameters to 7350 ** this function. ^(The second parameter is either the name of the database 7351 ** (i.e. "main", "temp", or an attached database) containing the specified 7352 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 7353 ** for the table using the same algorithm used by the database engine to 7354 ** resolve unqualified table references. 7355 ** 7356 ** ^The third and fourth parameters to this function are the table and column 7357 ** name of the desired column, respectively. 7358 ** 7359 ** ^Metadata is returned by writing to the memory locations passed as the 5th 7360 ** and subsequent parameters to this function. ^Any of these arguments may be 7361 ** NULL, in which case the corresponding element of metadata is omitted. 7362 ** 7363 ** ^(<blockquote> 7364 ** <table border="1"> 7365 ** <tr><th> Parameter <th> Output<br>Type <th> Description 7366 ** 7367 ** <tr><td> 5th <td> const char* <td> Data type 7368 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 7369 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 7370 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 7371 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 7372 ** </table> 7373 ** </blockquote>)^ 7374 ** 7375 ** ^The memory pointed to by the character pointers returned for the 7376 ** declaration type and collation sequence is valid until the next 7377 ** call to any SQLite API function. 7378 ** 7379 ** ^If the specified table is actually a view, an [error code] is returned. 7380 ** 7381 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 7382 ** is not a [WITHOUT ROWID] table and an 7383 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 7384 ** parameters are set for the explicitly declared column. ^(If there is no 7385 ** [INTEGER PRIMARY KEY] column, then the outputs 7386 ** for the [rowid] are set as follows: 7387 ** 7388 ** <pre> 7389 ** data type: "INTEGER" 7390 ** collation sequence: "BINARY" 7391 ** not null: 0 7392 ** primary key: 1 7393 ** auto increment: 0 7394 ** </pre>)^ 7395 ** 7396 ** ^This function causes all database schemas to be read from disk and 7397 ** parsed, if that has not already been done, and returns an error if 7398 ** any errors are encountered while loading the schema. 7399 */ 7400 SQLITE_API int sqlite3_table_column_metadata( 7401 sqlite3 *db, /* Connection handle */ 7402 const char *zDbName, /* Database name or NULL */ 7403 const char *zTableName, /* Table name */ 7404 const char *zColumnName, /* Column name */ 7405 char const **pzDataType, /* OUTPUT: Declared data type */ 7406 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 7407 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 7408 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 7409 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 7410 ); 7411 7412 /* 7413 ** CAPI3REF: Load An Extension 7414 ** METHOD: sqlite3 7415 ** 7416 ** ^This interface loads an SQLite extension library from the named file. 7417 ** 7418 ** ^The sqlite3_load_extension() interface attempts to load an 7419 ** [SQLite extension] library contained in the file zFile. If 7420 ** the file cannot be loaded directly, attempts are made to load 7421 ** with various operating-system specific extensions added. 7422 ** So for example, if "samplelib" cannot be loaded, then names like 7423 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 7424 ** be tried also. 7425 ** 7426 ** ^The entry point is zProc. 7427 ** ^(zProc may be 0, in which case SQLite will try to come up with an 7428 ** entry point name on its own. It first tries "sqlite3_extension_init". 7429 ** If that does not work, it constructs a name "sqlite3_X_init" where 7430 ** X consists of the lower-case equivalent of all ASCII alphabetic 7431 ** characters in the filename from the last "/" to the first following 7432 ** "." and omitting any initial "lib".)^ 7433 ** ^The sqlite3_load_extension() interface returns 7434 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 7435 ** ^If an error occurs and pzErrMsg is not 0, then the 7436 ** [sqlite3_load_extension()] interface shall attempt to 7437 ** fill *pzErrMsg with error message text stored in memory 7438 ** obtained from [sqlite3_malloc()]. The calling function 7439 ** should free this memory by calling [sqlite3_free()]. 7440 ** 7441 ** ^Extension loading must be enabled using 7442 ** [sqlite3_enable_load_extension()] or 7443 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 7444 ** prior to calling this API, 7445 ** otherwise an error will be returned. 7446 ** 7447 ** <b>Security warning:</b> It is recommended that the 7448 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 7449 ** interface. The use of the [sqlite3_enable_load_extension()] interface 7450 ** should be avoided. This will keep the SQL function [load_extension()] 7451 ** disabled and prevent SQL injections from giving attackers 7452 ** access to extension loading capabilities. 7453 ** 7454 ** See also the [load_extension() SQL function]. 7455 */ 7456 SQLITE_API int sqlite3_load_extension( 7457 sqlite3 *db, /* Load the extension into this database connection */ 7458 const char *zFile, /* Name of the shared library containing extension */ 7459 const char *zProc, /* Entry point. Derived from zFile if 0 */ 7460 char **pzErrMsg /* Put error message here if not 0 */ 7461 ); 7462 7463 /* 7464 ** CAPI3REF: Enable Or Disable Extension Loading 7465 ** METHOD: sqlite3 7466 ** 7467 ** ^So as not to open security holes in older applications that are 7468 ** unprepared to deal with [extension loading], and as a means of disabling 7469 ** [extension loading] while evaluating user-entered SQL, the following API 7470 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 7471 ** 7472 ** ^Extension loading is off by default. 7473 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 7474 ** to turn extension loading on and call it with onoff==0 to turn 7475 ** it back off again. 7476 ** 7477 ** ^This interface enables or disables both the C-API 7478 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 7479 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 7480 ** to enable or disable only the C-API.)^ 7481 ** 7482 ** <b>Security warning:</b> It is recommended that extension loading 7483 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 7484 ** rather than this interface, so the [load_extension()] SQL function 7485 ** remains disabled. This will prevent SQL injections from giving attackers 7486 ** access to extension loading capabilities. 7487 */ 7488 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 7489 7490 /* 7491 ** CAPI3REF: Automatically Load Statically Linked Extensions 7492 ** 7493 ** ^This interface causes the xEntryPoint() function to be invoked for 7494 ** each new [database connection] that is created. The idea here is that 7495 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 7496 ** that is to be automatically loaded into all new database connections. 7497 ** 7498 ** ^(Even though the function prototype shows that xEntryPoint() takes 7499 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 7500 ** arguments and expects an integer result as if the signature of the 7501 ** entry point were as follows: 7502 ** 7503 ** <blockquote><pre> 7504 ** int xEntryPoint( 7505 ** sqlite3 *db, 7506 ** const char **pzErrMsg, 7507 ** const struct sqlite3_api_routines *pThunk 7508 ** ); 7509 ** </pre></blockquote>)^ 7510 ** 7511 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 7512 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 7513 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 7514 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 7515 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 7516 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 7517 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 7518 ** 7519 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 7520 ** on the list of automatic extensions is a harmless no-op. ^No entry point 7521 ** will be called more than once for each database connection that is opened. 7522 ** 7523 ** See also: [sqlite3_reset_auto_extension()] 7524 ** and [sqlite3_cancel_auto_extension()] 7525 */ 7526 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 7527 7528 /* 7529 ** CAPI3REF: Cancel Automatic Extension Loading 7530 ** 7531 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 7532 ** initialization routine X that was registered using a prior call to 7533 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 7534 ** routine returns 1 if initialization routine X was successfully 7535 ** unregistered and it returns 0 if X was not on the list of initialization 7536 ** routines. 7537 */ 7538 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 7539 7540 /* 7541 ** CAPI3REF: Reset Automatic Extension Loading 7542 ** 7543 ** ^This interface disables all automatic extensions previously 7544 ** registered using [sqlite3_auto_extension()]. 7545 */ 7546 SQLITE_API void sqlite3_reset_auto_extension(void); 7547 7548 /* 7549 ** Structures used by the virtual table interface 7550 */ 7551 typedef struct sqlite3_vtab sqlite3_vtab; 7552 typedef struct sqlite3_index_info sqlite3_index_info; 7553 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7554 typedef struct sqlite3_module sqlite3_module; 7555 7556 /* 7557 ** CAPI3REF: Virtual Table Object 7558 ** KEYWORDS: sqlite3_module {virtual table module} 7559 ** 7560 ** This structure, sometimes called a "virtual table module", 7561 ** defines the implementation of a [virtual table]. 7562 ** This structure consists mostly of methods for the module. 7563 ** 7564 ** ^A virtual table module is created by filling in a persistent 7565 ** instance of this structure and passing a pointer to that instance 7566 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7567 ** ^The registration remains valid until it is replaced by a different 7568 ** module or until the [database connection] closes. The content 7569 ** of this structure must not change while it is registered with 7570 ** any database connection. 7571 */ 7572 struct sqlite3_module { 7573 int iVersion; 7574 int (*xCreate)(sqlite3*, void *pAux, 7575 int argc, const char *const*argv, 7576 sqlite3_vtab **ppVTab, char**); 7577 int (*xConnect)(sqlite3*, void *pAux, 7578 int argc, const char *const*argv, 7579 sqlite3_vtab **ppVTab, char**); 7580 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7581 int (*xDisconnect)(sqlite3_vtab *pVTab); 7582 int (*xDestroy)(sqlite3_vtab *pVTab); 7583 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7584 int (*xClose)(sqlite3_vtab_cursor*); 7585 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7586 int argc, sqlite3_value **argv); 7587 int (*xNext)(sqlite3_vtab_cursor*); 7588 int (*xEof)(sqlite3_vtab_cursor*); 7589 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7590 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7591 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7592 int (*xBegin)(sqlite3_vtab *pVTab); 7593 int (*xSync)(sqlite3_vtab *pVTab); 7594 int (*xCommit)(sqlite3_vtab *pVTab); 7595 int (*xRollback)(sqlite3_vtab *pVTab); 7596 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7597 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7598 void **ppArg); 7599 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7600 /* The methods above are in version 1 of the sqlite_module object. Those 7601 ** below are for version 2 and greater. */ 7602 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7603 int (*xRelease)(sqlite3_vtab *pVTab, int); 7604 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7605 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7606 ** Those below are for version 3 and greater. */ 7607 int (*xShadowName)(const char*); 7608 /* The methods above are in versions 1 through 3 of the sqlite_module object. 7609 ** Those below are for version 4 and greater. */ 7610 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema, 7611 const char *zTabName, int mFlags, char **pzErr); 7612 }; 7613 7614 /* 7615 ** CAPI3REF: Virtual Table Indexing Information 7616 ** KEYWORDS: sqlite3_index_info 7617 ** 7618 ** The sqlite3_index_info structure and its substructures is used as part 7619 ** of the [virtual table] interface to 7620 ** pass information into and receive the reply from the [xBestIndex] 7621 ** method of a [virtual table module]. The fields under **Inputs** are the 7622 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7623 ** results into the **Outputs** fields. 7624 ** 7625 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7626 ** 7627 ** <blockquote>column OP expr</blockquote> 7628 ** 7629 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7630 ** stored in aConstraint[].op using one of the 7631 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7632 ** ^(The index of the column is stored in 7633 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7634 ** expr on the right-hand side can be evaluated (and thus the constraint 7635 ** is usable) and false if it cannot.)^ 7636 ** 7637 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7638 ** and makes other simplifications to the WHERE clause in an attempt to 7639 ** get as many WHERE clause terms into the form shown above as possible. 7640 ** ^The aConstraint[] array only reports WHERE clause terms that are 7641 ** relevant to the particular virtual table being queried. 7642 ** 7643 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7644 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7645 ** 7646 ** The colUsed field indicates which columns of the virtual table may be 7647 ** required by the current scan. Virtual table columns are numbered from 7648 ** zero in the order in which they appear within the CREATE TABLE statement 7649 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7650 ** the corresponding bit is set within the colUsed mask if the column may be 7651 ** required by SQLite. If the table has at least 64 columns and any column 7652 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7653 ** set. In other words, column iCol may be required if the expression 7654 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7655 ** non-zero. 7656 ** 7657 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7658 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7659 ** the right-hand side of the corresponding aConstraint[] is evaluated 7660 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7661 ** is true, then the constraint is assumed to be fully handled by the 7662 ** virtual table and might not be checked again by the byte code.)^ ^(The 7663 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7664 ** is left in its default setting of false, the constraint will always be 7665 ** checked separately in byte code. If the omit flag is changed to true, then 7666 ** the constraint may or may not be checked in byte code. In other words, 7667 ** when the omit flag is true there is no guarantee that the constraint will 7668 ** not be checked again using byte code.)^ 7669 ** 7670 ** ^The idxNum and idxStr values are recorded and passed into the 7671 ** [xFilter] method. 7672 ** ^[sqlite3_free()] is used to free idxStr if and only if 7673 ** needToFreeIdxStr is true. 7674 ** 7675 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7676 ** the correct order to satisfy the ORDER BY clause so that no separate 7677 ** sorting step is required. 7678 ** 7679 ** ^The estimatedCost value is an estimate of the cost of a particular 7680 ** strategy. A cost of N indicates that the cost of the strategy is similar 7681 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7682 ** indicates that the expense of the operation is similar to that of a 7683 ** binary search on a unique indexed field of an SQLite table with N rows. 7684 ** 7685 ** ^The estimatedRows value is an estimate of the number of rows that 7686 ** will be returned by the strategy. 7687 ** 7688 ** The xBestIndex method may optionally populate the idxFlags field with a 7689 ** mask of SQLITE_INDEX_SCAN_* flags. One such flag is 7690 ** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN] 7691 ** output to show the idxNum as hex instead of as decimal. Another flag is 7692 ** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will 7693 ** return at most one row. 7694 ** 7695 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7696 ** SQLite also assumes that if a call to the xUpdate() method is made as 7697 ** part of the same statement to delete or update a virtual table row and the 7698 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7699 ** any database changes. In other words, if the xUpdate() returns 7700 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7701 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7702 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7703 ** the xUpdate method are automatically rolled back by SQLite. 7704 ** 7705 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7706 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7707 ** If a virtual table extension is 7708 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7709 ** to read or write the estimatedRows field are undefined (but are likely 7710 ** to include crashing the application). The estimatedRows field should 7711 ** therefore only be used if [sqlite3_libversion_number()] returns a 7712 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7713 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7714 ** It may therefore only be used if 7715 ** sqlite3_libversion_number() returns a value greater than or equal to 7716 ** 3009000. 7717 */ 7718 struct sqlite3_index_info { 7719 /* Inputs */ 7720 int nConstraint; /* Number of entries in aConstraint */ 7721 struct sqlite3_index_constraint { 7722 int iColumn; /* Column constrained. -1 for ROWID */ 7723 unsigned char op; /* Constraint operator */ 7724 unsigned char usable; /* True if this constraint is usable */ 7725 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7726 } *aConstraint; /* Table of WHERE clause constraints */ 7727 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7728 struct sqlite3_index_orderby { 7729 int iColumn; /* Column number */ 7730 unsigned char desc; /* True for DESC. False for ASC. */ 7731 } *aOrderBy; /* The ORDER BY clause */ 7732 /* Outputs */ 7733 struct sqlite3_index_constraint_usage { 7734 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7735 unsigned char omit; /* Do not code a test for this constraint */ 7736 } *aConstraintUsage; 7737 int idxNum; /* Number used to identify the index */ 7738 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7739 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7740 int orderByConsumed; /* True if output is already ordered */ 7741 double estimatedCost; /* Estimated cost of using this index */ 7742 /* Fields below are only available in SQLite 3.8.2 and later */ 7743 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7744 /* Fields below are only available in SQLite 3.9.0 and later */ 7745 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7746 /* Fields below are only available in SQLite 3.10.0 and later */ 7747 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7748 }; 7749 7750 /* 7751 ** CAPI3REF: Virtual Table Scan Flags 7752 ** 7753 ** Virtual table implementations are allowed to set the 7754 ** [sqlite3_index_info].idxFlags field to some combination of 7755 ** these bits. 7756 */ 7757 #define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */ 7758 #define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */ 7759 /* in EXPLAIN QUERY PLAN */ 7760 7761 /* 7762 ** CAPI3REF: Virtual Table Constraint Operator Codes 7763 ** 7764 ** These macros define the allowed values for the 7765 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7766 ** an operator that is part of a constraint term in the WHERE clause of 7767 ** a query that uses a [virtual table]. 7768 ** 7769 ** ^The left-hand operand of the operator is given by the corresponding 7770 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7771 ** operand is the rowid. 7772 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7773 ** operators have no left-hand operand, and so for those operators the 7774 ** corresponding aConstraint[].iColumn is meaningless and should not be 7775 ** used. 7776 ** 7777 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7778 ** value 255 are reserved to represent functions that are overloaded 7779 ** by the [xFindFunction|xFindFunction method] of the virtual table 7780 ** implementation. 7781 ** 7782 ** The right-hand operands for each constraint might be accessible using 7783 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7784 ** operand is only available if it appears as a single constant literal 7785 ** in the input SQL. If the right-hand operand is another column or an 7786 ** expression (even a constant expression) or a parameter, then the 7787 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7788 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7789 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7790 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7791 ** always return SQLITE_NOTFOUND. 7792 ** 7793 ** The collating sequence to be used for comparison can be found using 7794 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7795 ** tables, the collating sequence of constraints does not matter (for example 7796 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7797 ** interface is not commonly needed. 7798 */ 7799 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7800 #define SQLITE_INDEX_CONSTRAINT_GT 4 7801 #define SQLITE_INDEX_CONSTRAINT_LE 8 7802 #define SQLITE_INDEX_CONSTRAINT_LT 16 7803 #define SQLITE_INDEX_CONSTRAINT_GE 32 7804 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7805 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7806 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7807 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7808 #define SQLITE_INDEX_CONSTRAINT_NE 68 7809 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7810 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7811 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7812 #define SQLITE_INDEX_CONSTRAINT_IS 72 7813 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7814 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7815 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7816 7817 /* 7818 ** CAPI3REF: Register A Virtual Table Implementation 7819 ** METHOD: sqlite3 7820 ** 7821 ** ^These routines are used to register a new [virtual table module] name. 7822 ** ^Module names must be registered before 7823 ** creating a new [virtual table] using the module and before using a 7824 ** preexisting [virtual table] for the module. 7825 ** 7826 ** ^The module name is registered on the [database connection] specified 7827 ** by the first parameter. ^The name of the module is given by the 7828 ** second parameter. ^The third parameter is a pointer to 7829 ** the implementation of the [virtual table module]. ^The fourth 7830 ** parameter is an arbitrary client data pointer that is passed through 7831 ** into the [xCreate] and [xConnect] methods of the virtual table module 7832 ** when a new virtual table is being created or reinitialized. 7833 ** 7834 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7835 ** is a pointer to a destructor for the pClientData. ^SQLite will 7836 ** invoke the destructor function (if it is not NULL) when SQLite 7837 ** no longer needs the pClientData pointer. ^The destructor will also 7838 ** be invoked if the call to sqlite3_create_module_v2() fails. 7839 ** ^The sqlite3_create_module() 7840 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7841 ** destructor. 7842 ** 7843 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7844 ** NULL then no new module is created and any existing modules with the 7845 ** same name are dropped. 7846 ** 7847 ** See also: [sqlite3_drop_modules()] 7848 */ 7849 SQLITE_API int sqlite3_create_module( 7850 sqlite3 *db, /* SQLite connection to register module with */ 7851 const char *zName, /* Name of the module */ 7852 const sqlite3_module *p, /* Methods for the module */ 7853 void *pClientData /* Client data for xCreate/xConnect */ 7854 ); 7855 SQLITE_API int sqlite3_create_module_v2( 7856 sqlite3 *db, /* SQLite connection to register module with */ 7857 const char *zName, /* Name of the module */ 7858 const sqlite3_module *p, /* Methods for the module */ 7859 void *pClientData, /* Client data for xCreate/xConnect */ 7860 void(*xDestroy)(void*) /* Module destructor function */ 7861 ); 7862 7863 /* 7864 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7865 ** METHOD: sqlite3 7866 ** 7867 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7868 ** table modules from database connection D except those named on list L. 7869 ** The L parameter must be either NULL or a pointer to an array of pointers 7870 ** to strings where the array is terminated by a single NULL pointer. 7871 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7872 ** 7873 ** See also: [sqlite3_create_module()] 7874 */ 7875 SQLITE_API int sqlite3_drop_modules( 7876 sqlite3 *db, /* Remove modules from this connection */ 7877 const char **azKeep /* Except, do not remove the ones named here */ 7878 ); 7879 7880 /* 7881 ** CAPI3REF: Virtual Table Instance Object 7882 ** KEYWORDS: sqlite3_vtab 7883 ** 7884 ** Every [virtual table module] implementation uses a subclass 7885 ** of this object to describe a particular instance 7886 ** of the [virtual table]. Each subclass will 7887 ** be tailored to the specific needs of the module implementation. 7888 ** The purpose of this superclass is to define certain fields that are 7889 ** common to all module implementations. 7890 ** 7891 ** ^Virtual tables methods can set an error message by assigning a 7892 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7893 ** take care that any prior string is freed by a call to [sqlite3_free()] 7894 ** prior to assigning a new string to zErrMsg. ^After the error message 7895 ** is delivered up to the client application, the string will be automatically 7896 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7897 */ 7898 struct sqlite3_vtab { 7899 const sqlite3_module *pModule; /* The module for this virtual table */ 7900 int nRef; /* Number of open cursors */ 7901 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7902 /* Virtual table implementations will typically add additional fields */ 7903 }; 7904 7905 /* 7906 ** CAPI3REF: Virtual Table Cursor Object 7907 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7908 ** 7909 ** Every [virtual table module] implementation uses a subclass of the 7910 ** following structure to describe cursors that point into the 7911 ** [virtual table] and are used 7912 ** to loop through the virtual table. Cursors are created using the 7913 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7914 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7915 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7916 ** of the module. Each module implementation will define 7917 ** the content of a cursor structure to suit its own needs. 7918 ** 7919 ** This superclass exists in order to define fields of the cursor that 7920 ** are common to all implementations. 7921 */ 7922 struct sqlite3_vtab_cursor { 7923 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7924 /* Virtual table implementations will typically add additional fields */ 7925 }; 7926 7927 /* 7928 ** CAPI3REF: Declare The Schema Of A Virtual Table 7929 ** 7930 ** ^The [xCreate] and [xConnect] methods of a 7931 ** [virtual table module] call this interface 7932 ** to declare the format (the names and datatypes of the columns) of 7933 ** the virtual tables they implement. 7934 */ 7935 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7936 7937 /* 7938 ** CAPI3REF: Overload A Function For A Virtual Table 7939 ** METHOD: sqlite3 7940 ** 7941 ** ^(Virtual tables can provide alternative implementations of functions 7942 ** using the [xFindFunction] method of the [virtual table module]. 7943 ** But global versions of those functions 7944 ** must exist in order to be overloaded.)^ 7945 ** 7946 ** ^(This API makes sure a global version of a function with a particular 7947 ** name and number of parameters exists. If no such function exists 7948 ** before this API is called, a new function is created.)^ ^The implementation 7949 ** of the new function always causes an exception to be thrown. So 7950 ** the new function is not good for anything by itself. Its only 7951 ** purpose is to be a placeholder function that can be overloaded 7952 ** by a [virtual table]. 7953 */ 7954 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7955 7956 /* 7957 ** CAPI3REF: A Handle To An Open BLOB 7958 ** KEYWORDS: {BLOB handle} {BLOB handles} 7959 ** 7960 ** An instance of this object represents an open BLOB on which 7961 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7962 ** ^Objects of this type are created by [sqlite3_blob_open()] 7963 ** and destroyed by [sqlite3_blob_close()]. 7964 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7965 ** can be used to read or write small subsections of the BLOB. 7966 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7967 */ 7968 typedef struct sqlite3_blob sqlite3_blob; 7969 7970 /* 7971 ** CAPI3REF: Open A BLOB For Incremental I/O 7972 ** METHOD: sqlite3 7973 ** CONSTRUCTOR: sqlite3_blob 7974 ** 7975 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7976 ** in row iRow, column zColumn, table zTable in database zDb; 7977 ** in other words, the same BLOB that would be selected by: 7978 ** 7979 ** <pre> 7980 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7981 ** </pre>)^ 7982 ** 7983 ** ^(Parameter zDb is not the filename that contains the database, but 7984 ** rather the symbolic name of the database. For attached databases, this is 7985 ** the name that appears after the AS keyword in the [ATTACH] statement. 7986 ** For the main database file, the database name is "main". For TEMP 7987 ** tables, the database name is "temp".)^ 7988 ** 7989 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7990 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7991 ** read-only access. 7992 ** 7993 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7994 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7995 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7996 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7997 ** on *ppBlob after this function returns. 7998 ** 7999 ** This function fails with SQLITE_ERROR if any of the following are true: 8000 ** <ul> 8001 ** <li> ^(Database zDb does not exist)^, 8002 ** <li> ^(Table zTable does not exist within database zDb)^, 8003 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 8004 ** <li> ^(Column zColumn does not exist)^, 8005 ** <li> ^(Row iRow is not present in the table)^, 8006 ** <li> ^(The specified column of row iRow contains a value that is not 8007 ** a TEXT or BLOB value)^, 8008 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 8009 ** constraint and the blob is being opened for read/write access)^, 8010 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 8011 ** column zColumn is part of a [child key] definition and the blob is 8012 ** being opened for read/write access)^. 8013 ** </ul> 8014 ** 8015 ** ^Unless it returns SQLITE_MISUSE, this function sets the 8016 ** [database connection] error code and message accessible via 8017 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 8018 ** 8019 ** A BLOB referenced by sqlite3_blob_open() may be read using the 8020 ** [sqlite3_blob_read()] interface and modified by using 8021 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 8022 ** different row of the same table using the [sqlite3_blob_reopen()] 8023 ** interface. However, the column, table, or database of a [BLOB handle] 8024 ** cannot be changed after the [BLOB handle] is opened. 8025 ** 8026 ** ^(If the row that a BLOB handle points to is modified by an 8027 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 8028 ** then the BLOB handle is marked as "expired". 8029 ** This is true if any column of the row is changed, even a column 8030 ** other than the one the BLOB handle is open on.)^ 8031 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 8032 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 8033 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 8034 ** rolled back by the expiration of the BLOB. Such changes will eventually 8035 ** commit if the transaction continues to completion.)^ 8036 ** 8037 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 8038 ** the opened blob. ^The size of a blob may not be changed by this 8039 ** interface. Use the [UPDATE] SQL command to change the size of a 8040 ** blob. 8041 ** 8042 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 8043 ** and the built-in [zeroblob] SQL function may be used to create a 8044 ** zero-filled blob to read or write using the incremental-blob interface. 8045 ** 8046 ** To avoid a resource leak, every open [BLOB handle] should eventually 8047 ** be released by a call to [sqlite3_blob_close()]. 8048 ** 8049 ** See also: [sqlite3_blob_close()], 8050 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 8051 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 8052 */ 8053 SQLITE_API int sqlite3_blob_open( 8054 sqlite3*, 8055 const char *zDb, 8056 const char *zTable, 8057 const char *zColumn, 8058 sqlite3_int64 iRow, 8059 int flags, 8060 sqlite3_blob **ppBlob 8061 ); 8062 8063 /* 8064 ** CAPI3REF: Move a BLOB Handle to a New Row 8065 ** METHOD: sqlite3_blob 8066 ** 8067 ** ^This function is used to move an existing [BLOB handle] so that it points 8068 ** to a different row of the same database table. ^The new row is identified 8069 ** by the rowid value passed as the second argument. Only the row can be 8070 ** changed. ^The database, table and column on which the blob handle is open 8071 ** remain the same. Moving an existing [BLOB handle] to a new row is 8072 ** faster than closing the existing handle and opening a new one. 8073 ** 8074 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 8075 ** it must exist and there must be either a blob or text value stored in 8076 ** the nominated column.)^ ^If the new row is not present in the table, or if 8077 ** it does not contain a blob or text value, or if another error occurs, an 8078 ** SQLite error code is returned and the blob handle is considered aborted. 8079 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 8080 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 8081 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 8082 ** always returns zero. 8083 ** 8084 ** ^This function sets the database handle error code and message. 8085 */ 8086 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 8087 8088 /* 8089 ** CAPI3REF: Close A BLOB Handle 8090 ** DESTRUCTOR: sqlite3_blob 8091 ** 8092 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 8093 ** unconditionally. Even if this routine returns an error code, the 8094 ** handle is still closed.)^ 8095 ** 8096 ** ^If the blob handle being closed was opened for read-write access, and if 8097 ** the database is in auto-commit mode and there are no other open read-write 8098 ** blob handles or active write statements, the current transaction is 8099 ** committed. ^If an error occurs while committing the transaction, an error 8100 ** code is returned and the transaction rolled back. 8101 ** 8102 ** Calling this function with an argument that is not a NULL pointer or an 8103 ** open blob handle results in undefined behavior. ^Calling this routine 8104 ** with a null pointer (such as would be returned by a failed call to 8105 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 8106 ** is passed a valid open blob handle, the values returned by the 8107 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 8108 */ 8109 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 8110 8111 /* 8112 ** CAPI3REF: Return The Size Of An Open BLOB 8113 ** METHOD: sqlite3_blob 8114 ** 8115 ** ^Returns the size in bytes of the BLOB accessible via the 8116 ** successfully opened [BLOB handle] in its only argument. ^The 8117 ** incremental blob I/O routines can only read or overwrite existing 8118 ** blob content; they cannot change the size of a blob. 8119 ** 8120 ** This routine only works on a [BLOB handle] which has been created 8121 ** by a prior successful call to [sqlite3_blob_open()] and which has not 8122 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 8123 ** to this routine results in undefined and probably undesirable behavior. 8124 */ 8125 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 8126 8127 /* 8128 ** CAPI3REF: Read Data From A BLOB Incrementally 8129 ** METHOD: sqlite3_blob 8130 ** 8131 ** ^(This function is used to read data from an open [BLOB handle] into a 8132 ** caller-supplied buffer. N bytes of data are copied into buffer Z 8133 ** from the open BLOB, starting at offset iOffset.)^ 8134 ** 8135 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 8136 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 8137 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 8138 ** ^The size of the blob (and hence the maximum value of N+iOffset) 8139 ** can be determined using the [sqlite3_blob_bytes()] interface. 8140 ** 8141 ** ^An attempt to read from an expired [BLOB handle] fails with an 8142 ** error code of [SQLITE_ABORT]. 8143 ** 8144 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 8145 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 8146 ** 8147 ** This routine only works on a [BLOB handle] which has been created 8148 ** by a prior successful call to [sqlite3_blob_open()] and which has not 8149 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 8150 ** to this routine results in undefined and probably undesirable behavior. 8151 ** 8152 ** See also: [sqlite3_blob_write()]. 8153 */ 8154 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 8155 8156 /* 8157 ** CAPI3REF: Write Data Into A BLOB Incrementally 8158 ** METHOD: sqlite3_blob 8159 ** 8160 ** ^(This function is used to write data into an open [BLOB handle] from a 8161 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 8162 ** into the open BLOB, starting at offset iOffset.)^ 8163 ** 8164 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 8165 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 8166 ** ^Unless SQLITE_MISUSE is returned, this function sets the 8167 ** [database connection] error code and message accessible via 8168 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 8169 ** 8170 ** ^If the [BLOB handle] passed as the first argument was not opened for 8171 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 8172 ** this function returns [SQLITE_READONLY]. 8173 ** 8174 ** This function may only modify the contents of the BLOB; it is 8175 ** not possible to increase the size of a BLOB using this API. 8176 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 8177 ** [SQLITE_ERROR] is returned and no data is written. The size of the 8178 ** BLOB (and hence the maximum value of N+iOffset) can be determined 8179 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 8180 ** than zero [SQLITE_ERROR] is returned and no data is written. 8181 ** 8182 ** ^An attempt to write to an expired [BLOB handle] fails with an 8183 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 8184 ** before the [BLOB handle] expired are not rolled back by the 8185 ** expiration of the handle, though of course those changes might 8186 ** have been overwritten by the statement that expired the BLOB handle 8187 ** or by other independent statements. 8188 ** 8189 ** This routine only works on a [BLOB handle] which has been created 8190 ** by a prior successful call to [sqlite3_blob_open()] and which has not 8191 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 8192 ** to this routine results in undefined and probably undesirable behavior. 8193 ** 8194 ** See also: [sqlite3_blob_read()]. 8195 */ 8196 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 8197 8198 /* 8199 ** CAPI3REF: Virtual File System Objects 8200 ** 8201 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 8202 ** that SQLite uses to interact 8203 ** with the underlying operating system. Most SQLite builds come with a 8204 ** single default VFS that is appropriate for the host computer. 8205 ** New VFSes can be registered and existing VFSes can be unregistered. 8206 ** The following interfaces are provided. 8207 ** 8208 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 8209 ** ^Names are case sensitive. 8210 ** ^Names are zero-terminated UTF-8 strings. 8211 ** ^If there is no match, a NULL pointer is returned. 8212 ** ^If zVfsName is NULL then the default VFS is returned. 8213 ** 8214 ** ^New VFSes are registered with sqlite3_vfs_register(). 8215 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 8216 ** ^The same VFS can be registered multiple times without injury. 8217 ** ^To make an existing VFS into the default VFS, register it again 8218 ** with the makeDflt flag set. If two different VFSes with the 8219 ** same name are registered, the behavior is undefined. If a 8220 ** VFS is registered with a name that is NULL or an empty string, 8221 ** then the behavior is undefined. 8222 ** 8223 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 8224 ** ^(If the default VFS is unregistered, another VFS is chosen as 8225 ** the default. The choice for the new VFS is arbitrary.)^ 8226 */ 8227 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 8228 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 8229 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 8230 8231 /* 8232 ** CAPI3REF: Mutexes 8233 ** 8234 ** The SQLite core uses these routines for thread 8235 ** synchronization. Though they are intended for internal 8236 ** use by SQLite, code that links against SQLite is 8237 ** permitted to use any of these routines. 8238 ** 8239 ** The SQLite source code contains multiple implementations 8240 ** of these mutex routines. An appropriate implementation 8241 ** is selected automatically at compile-time. The following 8242 ** implementations are available in the SQLite core: 8243 ** 8244 ** <ul> 8245 ** <li> SQLITE_MUTEX_PTHREADS 8246 ** <li> SQLITE_MUTEX_W32 8247 ** <li> SQLITE_MUTEX_NOOP 8248 ** </ul> 8249 ** 8250 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 8251 ** that does no real locking and is appropriate for use in 8252 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 8253 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 8254 ** and Windows. 8255 ** 8256 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 8257 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 8258 ** implementation is included with the library. In this case the 8259 ** application must supply a custom mutex implementation using the 8260 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 8261 ** before calling sqlite3_initialize() or any other public sqlite3_ 8262 ** function that calls sqlite3_initialize(). 8263 ** 8264 ** ^The sqlite3_mutex_alloc() routine allocates a new 8265 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 8266 ** routine returns NULL if it is unable to allocate the requested 8267 ** mutex. The argument to sqlite3_mutex_alloc() must be one of these 8268 ** integer constants: 8269 ** 8270 ** <ul> 8271 ** <li> SQLITE_MUTEX_FAST 8272 ** <li> SQLITE_MUTEX_RECURSIVE 8273 ** <li> SQLITE_MUTEX_STATIC_MAIN 8274 ** <li> SQLITE_MUTEX_STATIC_MEM 8275 ** <li> SQLITE_MUTEX_STATIC_OPEN 8276 ** <li> SQLITE_MUTEX_STATIC_PRNG 8277 ** <li> SQLITE_MUTEX_STATIC_LRU 8278 ** <li> SQLITE_MUTEX_STATIC_PMEM 8279 ** <li> SQLITE_MUTEX_STATIC_APP1 8280 ** <li> SQLITE_MUTEX_STATIC_APP2 8281 ** <li> SQLITE_MUTEX_STATIC_APP3 8282 ** <li> SQLITE_MUTEX_STATIC_VFS1 8283 ** <li> SQLITE_MUTEX_STATIC_VFS2 8284 ** <li> SQLITE_MUTEX_STATIC_VFS3 8285 ** </ul> 8286 ** 8287 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 8288 ** cause sqlite3_mutex_alloc() to create 8289 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 8290 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 8291 ** The mutex implementation does not need to make a distinction 8292 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 8293 ** not want to. SQLite will only request a recursive mutex in 8294 ** cases where it really needs one. If a faster non-recursive mutex 8295 ** implementation is available on the host platform, the mutex subsystem 8296 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 8297 ** 8298 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 8299 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 8300 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 8301 ** used by the current version of SQLite. Future versions of SQLite 8302 ** may add additional static mutexes. Static mutexes are for internal 8303 ** use by SQLite only. Applications that use SQLite mutexes should 8304 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 8305 ** SQLITE_MUTEX_RECURSIVE. 8306 ** 8307 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 8308 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 8309 ** returns a different mutex on every call. ^For the static 8310 ** mutex types, the same mutex is returned on every call that has 8311 ** the same type number. 8312 ** 8313 ** ^The sqlite3_mutex_free() routine deallocates a previously 8314 ** allocated dynamic mutex. Attempting to deallocate a static 8315 ** mutex results in undefined behavior. 8316 ** 8317 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 8318 ** to enter a mutex. ^If another thread is already within the mutex, 8319 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 8320 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 8321 ** upon successful entry. ^(Mutexes created using 8322 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 8323 ** In such cases, the 8324 ** mutex must be exited an equal number of times before another thread 8325 ** can enter.)^ If the same thread tries to enter any mutex other 8326 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 8327 ** 8328 ** ^(Some systems (for example, Windows 95) do not support the operation 8329 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 8330 ** will always return SQLITE_BUSY. In most cases the SQLite core only uses 8331 ** sqlite3_mutex_try() as an optimization, so this is acceptable 8332 ** behavior. The exceptions are unix builds that set the 8333 ** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working 8334 ** sqlite3_mutex_try() is required.)^ 8335 ** 8336 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 8337 ** previously entered by the same thread. The behavior 8338 ** is undefined if the mutex is not currently entered by the 8339 ** calling thread or is not currently allocated. 8340 ** 8341 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), 8342 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer, 8343 ** then any of the four routines behaves as a no-op. 8344 ** 8345 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 8346 */ 8347 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 8348 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 8349 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 8350 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 8351 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 8352 8353 /* 8354 ** CAPI3REF: Mutex Methods Object 8355 ** 8356 ** An instance of this structure defines the low-level routines 8357 ** used to allocate and use mutexes. 8358 ** 8359 ** Usually, the default mutex implementations provided by SQLite are 8360 ** sufficient, however the application has the option of substituting a custom 8361 ** implementation for specialized deployments or systems for which SQLite 8362 ** does not provide a suitable implementation. In this case, the application 8363 ** creates and populates an instance of this structure to pass 8364 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 8365 ** Additionally, an instance of this structure can be used as an 8366 ** output variable when querying the system for the current mutex 8367 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 8368 ** 8369 ** ^The xMutexInit method defined by this structure is invoked as 8370 ** part of system initialization by the sqlite3_initialize() function. 8371 ** ^The xMutexInit routine is called by SQLite exactly once for each 8372 ** effective call to [sqlite3_initialize()]. 8373 ** 8374 ** ^The xMutexEnd method defined by this structure is invoked as 8375 ** part of system shutdown by the sqlite3_shutdown() function. The 8376 ** implementation of this method is expected to release all outstanding 8377 ** resources obtained by the mutex methods implementation, especially 8378 ** those obtained by the xMutexInit method. ^The xMutexEnd() 8379 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 8380 ** 8381 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 8382 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 8383 ** xMutexNotheld) implement the following interfaces (respectively): 8384 ** 8385 ** <ul> 8386 ** <li> [sqlite3_mutex_alloc()] </li> 8387 ** <li> [sqlite3_mutex_free()] </li> 8388 ** <li> [sqlite3_mutex_enter()] </li> 8389 ** <li> [sqlite3_mutex_try()] </li> 8390 ** <li> [sqlite3_mutex_leave()] </li> 8391 ** <li> [sqlite3_mutex_held()] </li> 8392 ** <li> [sqlite3_mutex_notheld()] </li> 8393 ** </ul>)^ 8394 ** 8395 ** The only difference is that the public sqlite3_XXX functions enumerated 8396 ** above silently ignore any invocations that pass a NULL pointer instead 8397 ** of a valid mutex handle. The implementations of the methods defined 8398 ** by this structure are not required to handle this case. The results 8399 ** of passing a NULL pointer instead of a valid mutex handle are undefined 8400 ** (i.e. it is acceptable to provide an implementation that segfaults if 8401 ** it is passed a NULL pointer). 8402 ** 8403 ** The xMutexInit() method must be threadsafe. It must be harmless to 8404 ** invoke xMutexInit() multiple times within the same process and without 8405 ** intervening calls to xMutexEnd(). Second and subsequent calls to 8406 ** xMutexInit() must be no-ops. 8407 ** 8408 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 8409 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 8410 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 8411 ** memory allocation for a fast or recursive mutex. 8412 ** 8413 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 8414 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 8415 ** If xMutexInit fails in any way, it is expected to clean up after itself 8416 ** prior to returning. 8417 */ 8418 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 8419 struct sqlite3_mutex_methods { 8420 int (*xMutexInit)(void); 8421 int (*xMutexEnd)(void); 8422 sqlite3_mutex *(*xMutexAlloc)(int); 8423 void (*xMutexFree)(sqlite3_mutex *); 8424 void (*xMutexEnter)(sqlite3_mutex *); 8425 int (*xMutexTry)(sqlite3_mutex *); 8426 void (*xMutexLeave)(sqlite3_mutex *); 8427 int (*xMutexHeld)(sqlite3_mutex *); 8428 int (*xMutexNotheld)(sqlite3_mutex *); 8429 }; 8430 8431 /* 8432 ** CAPI3REF: Mutex Verification Routines 8433 ** 8434 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 8435 ** are intended for use inside assert() statements. The SQLite core 8436 ** never uses these routines except inside an assert() and applications 8437 ** are advised to follow the lead of the core. The SQLite core only 8438 ** provides implementations for these routines when it is compiled 8439 ** with the SQLITE_DEBUG flag. External mutex implementations 8440 ** are only required to provide these routines if SQLITE_DEBUG is 8441 ** defined and if NDEBUG is not defined. 8442 ** 8443 ** These routines should return true if the mutex in their argument 8444 ** is held or not held, respectively, by the calling thread. 8445 ** 8446 ** The implementation is not required to provide versions of these 8447 ** routines that actually work. If the implementation does not provide working 8448 ** versions of these routines, it should at least provide stubs that always 8449 ** return true so that one does not get spurious assertion failures. 8450 ** 8451 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 8452 ** the routine should return 1. This seems counter-intuitive since 8453 ** clearly the mutex cannot be held if it does not exist. But 8454 ** the reason the mutex does not exist is because the build is not 8455 ** using mutexes. And we do not want the assert() containing the 8456 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 8457 ** the appropriate thing to do. The sqlite3_mutex_notheld() 8458 ** interface should also return 1 when given a NULL pointer. 8459 */ 8460 #ifndef NDEBUG 8461 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 8462 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 8463 #endif 8464 8465 /* 8466 ** CAPI3REF: Mutex Types 8467 ** 8468 ** The [sqlite3_mutex_alloc()] interface takes a single argument 8469 ** which is one of these integer constants. 8470 ** 8471 ** The set of static mutexes may change from one SQLite release to the 8472 ** next. Applications that override the built-in mutex logic must be 8473 ** prepared to accommodate additional static mutexes. 8474 */ 8475 #define SQLITE_MUTEX_FAST 0 8476 #define SQLITE_MUTEX_RECURSIVE 1 8477 #define SQLITE_MUTEX_STATIC_MAIN 2 8478 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 8479 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 8480 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 8481 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 8482 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 8483 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 8484 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 8485 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 8486 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 8487 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 8488 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 8489 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 8490 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 8491 8492 /* Legacy compatibility: */ 8493 #define SQLITE_MUTEX_STATIC_MASTER 2 8494 8495 8496 /* 8497 ** CAPI3REF: Retrieve the mutex for a database connection 8498 ** METHOD: sqlite3 8499 ** 8500 ** ^This interface returns a pointer to the [sqlite3_mutex] object that 8501 ** serializes access to the [database connection] given in the argument 8502 ** when the [threading mode] is Serialized. 8503 ** ^If the [threading mode] is Single-thread or Multi-thread then this 8504 ** routine returns a NULL pointer. 8505 */ 8506 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 8507 8508 /* 8509 ** CAPI3REF: Low-Level Control Of Database Files 8510 ** METHOD: sqlite3 8511 ** KEYWORDS: {file control} 8512 ** 8513 ** ^The [sqlite3_file_control()] interface makes a direct call to the 8514 ** xFileControl method for the [sqlite3_io_methods] object associated 8515 ** with a particular database identified by the second argument. ^The 8516 ** name of the database is "main" for the main database or "temp" for the 8517 ** TEMP database, or the name that appears after the AS keyword for 8518 ** databases that are added using the [ATTACH] SQL command. 8519 ** ^A NULL pointer can be used in place of "main" to refer to the 8520 ** main database file. 8521 ** ^The third and fourth parameters to this routine 8522 ** are passed directly through to the second and third parameters of 8523 ** the xFileControl method. ^The return value of the xFileControl 8524 ** method becomes the return value of this routine. 8525 ** 8526 ** A few opcodes for [sqlite3_file_control()] are handled directly 8527 ** by the SQLite core and never invoke the 8528 ** sqlite3_io_methods.xFileControl method. 8529 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 8530 ** a pointer to the underlying [sqlite3_file] object to be written into 8531 ** the space pointed to by the 4th parameter. The 8532 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 8533 ** the [sqlite3_file] object associated with the journal file instead of 8534 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 8535 ** a pointer to the underlying [sqlite3_vfs] object for the file. 8536 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 8537 ** from the pager. 8538 ** 8539 ** ^If the second parameter (zDbName) does not match the name of any 8540 ** open database file, then SQLITE_ERROR is returned. ^This error 8541 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 8542 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 8543 ** also return SQLITE_ERROR. There is no way to distinguish between 8544 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8545 ** xFileControl method. 8546 ** 8547 ** See also: [file control opcodes] 8548 */ 8549 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8550 8551 /* 8552 ** CAPI3REF: Testing Interface 8553 ** 8554 ** ^The sqlite3_test_control() interface is used to read out internal 8555 ** state of SQLite and to inject faults into SQLite for testing 8556 ** purposes. ^The first parameter is an operation code that determines 8557 ** the number, meaning, and operation of all subsequent parameters. 8558 ** 8559 ** This interface is not for use by applications. It exists solely 8560 ** for verifying the correct operation of the SQLite library. Depending 8561 ** on how the SQLite library is compiled, this interface might not exist. 8562 ** 8563 ** The details of the operation codes, their meanings, the parameters 8564 ** they take, and what they do are all subject to change without notice. 8565 ** Unlike most of the SQLite API, this function is not guaranteed to 8566 ** operate consistently from one release to the next. 8567 */ 8568 SQLITE_API int sqlite3_test_control(int op, ...); 8569 8570 /* 8571 ** CAPI3REF: Testing Interface Operation Codes 8572 ** 8573 ** These constants are the valid operation code parameters used 8574 ** as the first argument to [sqlite3_test_control()]. 8575 ** 8576 ** These parameters and their meanings are subject to change 8577 ** without notice. These values are for testing purposes only. 8578 ** Applications should not use any of these parameters or the 8579 ** [sqlite3_test_control()] interface. 8580 */ 8581 #define SQLITE_TESTCTRL_FIRST 5 8582 #define SQLITE_TESTCTRL_PRNG_SAVE 5 8583 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 8584 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8585 #define SQLITE_TESTCTRL_FK_NO_ACTION 7 8586 #define SQLITE_TESTCTRL_BITVEC_TEST 8 8587 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 8588 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8589 #define SQLITE_TESTCTRL_PENDING_BYTE 11 8590 #define SQLITE_TESTCTRL_ASSERT 12 8591 #define SQLITE_TESTCTRL_ALWAYS 13 8592 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8593 #define SQLITE_TESTCTRL_JSON_SELFCHECK 14 8594 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8595 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8596 #define SQLITE_TESTCTRL_GETOPT 16 8597 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8598 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8599 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8600 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8601 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8602 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8603 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8604 #define SQLITE_TESTCTRL_BYTEORDER 22 8605 #define SQLITE_TESTCTRL_ISINIT 23 8606 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8607 #define SQLITE_TESTCTRL_IMPOSTER 25 8608 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8609 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8610 #define SQLITE_TESTCTRL_PRNG_SEED 28 8611 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8612 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8613 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8614 #define SQLITE_TESTCTRL_TUNE 32 8615 #define SQLITE_TESTCTRL_LOGEST 33 8616 #define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */ 8617 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */ 8618 8619 /* 8620 ** CAPI3REF: SQL Keyword Checking 8621 ** 8622 ** These routines provide access to the set of SQL language keywords 8623 ** recognized by SQLite. Applications can use these routines to determine 8624 ** whether or not a specific identifier needs to be escaped (for example, 8625 ** by enclosing in double-quotes) so as not to confuse the parser. 8626 ** 8627 ** The sqlite3_keyword_count() interface returns the number of distinct 8628 ** keywords understood by SQLite. 8629 ** 8630 ** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and 8631 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8632 ** of bytes in the keyword into *L. The string that *Z points to is not 8633 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8634 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8635 ** or L are NULL or invalid pointers then calls to 8636 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8637 ** 8638 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8639 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8640 ** if it is and zero if not. 8641 ** 8642 ** The parser used by SQLite is forgiving. It is often possible to use 8643 ** a keyword as an identifier as long as such use does not result in a 8644 ** parsing ambiguity. For example, the statement 8645 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8646 ** creates a new table named "BEGIN" with three columns named 8647 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8648 ** using keywords as identifiers. Common techniques used to avoid keyword 8649 ** name collisions include: 8650 ** <ul> 8651 ** <li> Put all identifier names inside double-quotes. This is the official 8652 ** SQL way to escape identifier names. 8653 ** <li> Put identifier names inside [...]. This is not standard SQL, 8654 ** but it is what SQL Server does and so lots of programmers use this 8655 ** technique. 8656 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8657 ** with "Z". 8658 ** <li> Include a digit somewhere in every identifier name. 8659 ** </ul> 8660 ** 8661 ** Note that the number of keywords understood by SQLite can depend on 8662 ** compile-time options. For example, "VACUUM" is not a keyword if 8663 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8664 ** new keywords may be added to future releases of SQLite. 8665 */ 8666 SQLITE_API int sqlite3_keyword_count(void); 8667 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8668 SQLITE_API int sqlite3_keyword_check(const char*,int); 8669 8670 /* 8671 ** CAPI3REF: Dynamic String Object 8672 ** KEYWORDS: {dynamic string} 8673 ** 8674 ** An instance of the sqlite3_str object contains a dynamically-sized 8675 ** string under construction. 8676 ** 8677 ** The lifecycle of an sqlite3_str object is as follows: 8678 ** <ol> 8679 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8680 ** <li> ^Text is appended to the sqlite3_str object using various 8681 ** methods, such as [sqlite3_str_appendf()]. 8682 ** <li> ^The sqlite3_str object is destroyed and the string it created 8683 ** is returned using the [sqlite3_str_finish()] interface. 8684 ** </ol> 8685 */ 8686 typedef struct sqlite3_str sqlite3_str; 8687 8688 /* 8689 ** CAPI3REF: Create A New Dynamic String Object 8690 ** CONSTRUCTOR: sqlite3_str 8691 ** 8692 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8693 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8694 ** [sqlite3_str_new()] must be freed by a subsequent call to 8695 ** [sqlite3_str_finish(X)]. 8696 ** 8697 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8698 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8699 ** error the returned object might be a special singleton that will 8700 ** silently reject new text, always return SQLITE_NOMEM from 8701 ** [sqlite3_str_errcode()], always return 0 for 8702 ** [sqlite3_str_length()], and always return NULL from 8703 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8704 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8705 ** to any of the other [sqlite3_str] methods. 8706 ** 8707 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8708 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8709 ** length of the string contained in the [sqlite3_str] object will be 8710 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8711 ** of [SQLITE_MAX_LENGTH]. 8712 */ 8713 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8714 8715 /* 8716 ** CAPI3REF: Finalize A Dynamic String 8717 ** DESTRUCTOR: sqlite3_str 8718 ** 8719 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8720 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8721 ** that contains the constructed string. The calling application should 8722 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8723 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8724 ** errors were encountered during construction of the string. ^The 8725 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8726 ** string in [sqlite3_str] object X is zero bytes long. 8727 */ 8728 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8729 8730 /* 8731 ** CAPI3REF: Add Content To A Dynamic String 8732 ** METHOD: sqlite3_str 8733 ** 8734 ** These interfaces add content to an sqlite3_str object previously obtained 8735 ** from [sqlite3_str_new()]. 8736 ** 8737 ** ^The [sqlite3_str_appendf(X,F,...)] and 8738 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8739 ** functionality of SQLite to append formatted text onto the end of 8740 ** [sqlite3_str] object X. 8741 ** 8742 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8743 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8744 ** S must contain at least N non-zero bytes of content. To append a 8745 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8746 ** method instead. 8747 ** 8748 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8749 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8750 ** 8751 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8752 ** single-byte character C onto the end of [sqlite3_str] object X. 8753 ** ^This method can be used, for example, to add whitespace indentation. 8754 ** 8755 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8756 ** inside [sqlite3_str] object X back to zero bytes in length. 8757 ** 8758 ** These methods do not return a result code. ^If an error occurs, that fact 8759 ** is recorded in the [sqlite3_str] object and can be recovered by a 8760 ** subsequent call to [sqlite3_str_errcode(X)]. 8761 */ 8762 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8763 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8764 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8765 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8766 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8767 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8768 8769 /* 8770 ** CAPI3REF: Status Of A Dynamic String 8771 ** METHOD: sqlite3_str 8772 ** 8773 ** These interfaces return the current status of an [sqlite3_str] object. 8774 ** 8775 ** ^If any prior errors have occurred while constructing the dynamic string 8776 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8777 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8778 ** [SQLITE_NOMEM] following any out-of-memory error, or 8779 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8780 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8781 ** 8782 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8783 ** of the dynamic string under construction in [sqlite3_str] object X. 8784 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8785 ** zero-termination byte. 8786 ** 8787 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8788 ** content of the dynamic string under construction in X. The value 8789 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8790 ** and might be freed or altered by any subsequent method on the same 8791 ** [sqlite3_str] object. Applications must not use the pointer returned by 8792 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8793 ** object. ^Applications may change the content of the string returned 8794 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8795 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8796 ** write any byte after any subsequent sqlite3_str method call. 8797 */ 8798 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8799 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8800 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8801 8802 /* 8803 ** CAPI3REF: SQLite Runtime Status 8804 ** 8805 ** ^These interfaces are used to retrieve runtime status information 8806 ** about the performance of SQLite, and optionally to reset various 8807 ** highwater marks. ^The first argument is an integer code for 8808 ** the specific parameter to measure. ^(Recognized integer codes 8809 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8810 ** ^The current value of the parameter is returned into *pCurrent. 8811 ** ^The highest recorded value is returned in *pHighwater. ^If the 8812 ** resetFlag is true, then the highest record value is reset after 8813 ** *pHighwater is written. ^(Some parameters do not record the highest 8814 ** value. For those parameters 8815 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8816 ** ^(Other parameters record only the highwater mark and not the current 8817 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8818 ** 8819 ** ^The sqlite3_status() and sqlite3_status64() routines return 8820 ** SQLITE_OK on success and a non-zero [error code] on failure. 8821 ** 8822 ** If either the current value or the highwater mark is too large to 8823 ** be represented by a 32-bit integer, then the values returned by 8824 ** sqlite3_status() are undefined. 8825 ** 8826 ** See also: [sqlite3_db_status()] 8827 */ 8828 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8829 SQLITE_API int sqlite3_status64( 8830 int op, 8831 sqlite3_int64 *pCurrent, 8832 sqlite3_int64 *pHighwater, 8833 int resetFlag 8834 ); 8835 8836 8837 /* 8838 ** CAPI3REF: Status Parameters 8839 ** KEYWORDS: {status parameters} 8840 ** 8841 ** These integer constants designate various run-time status parameters 8842 ** that can be returned by [sqlite3_status()]. 8843 ** 8844 ** <dl> 8845 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8846 ** <dd>This parameter is the current amount of memory checked out 8847 ** using [sqlite3_malloc()], either directly or indirectly. The 8848 ** figure includes calls made to [sqlite3_malloc()] by the application 8849 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8850 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8851 ** this parameter. The amount returned is the sum of the allocation 8852 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8853 ** 8854 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8855 ** <dd>This parameter records the largest memory allocation request 8856 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8857 ** internal equivalents). Only the value returned in the 8858 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8859 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8860 ** 8861 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8862 ** <dd>This parameter records the number of separate memory allocations 8863 ** currently checked out.</dd>)^ 8864 ** 8865 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8866 ** <dd>This parameter returns the number of pages used out of the 8867 ** [pagecache memory allocator] that was configured using 8868 ** [SQLITE_CONFIG_PAGECACHE]. The 8869 ** value returned is in pages, not in bytes.</dd>)^ 8870 ** 8871 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8872 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8873 ** <dd>This parameter returns the number of bytes of page cache 8874 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8875 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8876 ** returned value includes allocations that overflowed because they 8877 ** were too large (they were larger than the "sz" parameter to 8878 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8879 ** no space was left in the page cache.</dd>)^ 8880 ** 8881 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8882 ** <dd>This parameter records the largest memory allocation request 8883 ** handed to the [pagecache memory allocator]. Only the value returned in the 8884 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8885 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8886 ** 8887 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8888 ** <dd>No longer used.</dd> 8889 ** 8890 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8891 ** <dd>No longer used.</dd> 8892 ** 8893 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8894 ** <dd>No longer used.</dd> 8895 ** 8896 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8897 ** <dd>The *pHighwater parameter records the deepest parser stack. 8898 ** The *pCurrent value is undefined. The *pHighwater value is only 8899 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8900 ** </dl> 8901 ** 8902 ** New status parameters may be added from time to time. 8903 */ 8904 #define SQLITE_STATUS_MEMORY_USED 0 8905 #define SQLITE_STATUS_PAGECACHE_USED 1 8906 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8907 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8908 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8909 #define SQLITE_STATUS_MALLOC_SIZE 5 8910 #define SQLITE_STATUS_PARSER_STACK 6 8911 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8912 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8913 #define SQLITE_STATUS_MALLOC_COUNT 9 8914 8915 /* 8916 ** CAPI3REF: Database Connection Status 8917 ** METHOD: sqlite3 8918 ** 8919 ** ^This interface is used to retrieve runtime status information 8920 ** about a single [database connection]. ^The first argument is the 8921 ** database connection object to be interrogated. ^The second argument 8922 ** is an integer constant, taken from the set of 8923 ** [SQLITE_DBSTATUS options], that 8924 ** determines the parameter to interrogate. The set of 8925 ** [SQLITE_DBSTATUS options] is likely 8926 ** to grow in future releases of SQLite. 8927 ** 8928 ** ^The current value of the requested parameter is written into *pCur 8929 ** and the highest instantaneous value is written into *pHiwtr. ^If 8930 ** the resetFlg is true, then the highest instantaneous value is 8931 ** reset back down to the current value. 8932 ** 8933 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8934 ** non-zero [error code] on failure. 8935 ** 8936 ** ^The sqlite3_db_status64(D,O,C,H,R) routine works exactly the same 8937 ** way as sqlite3_db_status(D,O,C,H,R) routine except that the C and H 8938 ** parameters are pointer to 64-bit integers (type: sqlite3_int64) instead 8939 ** of pointers to 32-bit integers, which allows larger status values 8940 ** to be returned. If a status value exceeds 2,147,483,647 then 8941 ** sqlite3_db_status() will truncate the value whereas sqlite3_db_status64() 8942 ** will return the full value. 8943 ** 8944 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8945 */ 8946 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8947 SQLITE_API int sqlite3_db_status64(sqlite3*,int,sqlite3_int64*,sqlite3_int64*,int); 8948 8949 /* 8950 ** CAPI3REF: Status Parameters for database connections 8951 ** KEYWORDS: {SQLITE_DBSTATUS options} 8952 ** 8953 ** These constants are the available integer "verbs" that can be passed as 8954 ** the second argument to the [sqlite3_db_status()] interface. 8955 ** 8956 ** New verbs may be added in future releases of SQLite. Existing verbs 8957 ** might be discontinued. Applications should check the return code from 8958 ** [sqlite3_db_status()] to make sure that the call worked. 8959 ** The [sqlite3_db_status()] interface will return a non-zero error code 8960 ** if a discontinued or unsupported verb is invoked. 8961 ** 8962 ** <dl> 8963 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8964 ** <dd>This parameter returns the number of lookaside memory slots currently 8965 ** checked out.</dd>)^ 8966 ** 8967 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8968 ** <dd>This parameter returns the number of malloc attempts that were 8969 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8970 ** the current value is always zero.</dd>)^ 8971 ** 8972 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8973 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8974 ** <dd>This parameter returns the number of malloc attempts that might have 8975 ** been satisfied using lookaside memory but failed due to the amount of 8976 ** memory requested being larger than the lookaside slot size. 8977 ** Only the high-water value is meaningful; 8978 ** the current value is always zero.</dd>)^ 8979 ** 8980 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8981 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8982 ** <dd>This parameter returns the number of malloc attempts that might have 8983 ** been satisfied using lookaside memory but failed due to all lookaside 8984 ** memory already being in use. 8985 ** Only the high-water value is meaningful; 8986 ** the current value is always zero.</dd>)^ 8987 ** 8988 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8989 ** <dd>This parameter returns the approximate number of bytes of heap 8990 ** memory used by all pager caches associated with the database connection.)^ 8991 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8992 ** </dd> 8993 ** 8994 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8995 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8996 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8997 ** pager cache is shared between two or more connections the bytes of heap 8998 ** memory used by that pager cache is divided evenly between the attached 8999 ** connections.)^ In other words, if none of the pager caches associated 9000 ** with the database connection are shared, this request returns the same 9001 ** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are 9002 ** shared, the value returned by this call will be smaller than that returned 9003 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 9004 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd> 9005 ** 9006 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 9007 ** <dd>This parameter returns the approximate number of bytes of heap 9008 ** memory used to store the schema for all databases associated 9009 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 9010 ** ^The full amount of memory used by the schemas is reported, even if the 9011 ** schema memory is shared with other database connections due to 9012 ** [shared cache mode] being enabled. 9013 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 9014 ** </dd> 9015 ** 9016 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 9017 ** <dd>This parameter returns the approximate number of bytes of heap 9018 ** and lookaside memory used by all prepared statements associated with 9019 ** the database connection.)^ 9020 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 9021 ** </dd> 9022 ** 9023 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 9024 ** <dd>This parameter returns the number of pager cache hits that have 9025 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 9026 ** is always 0. 9027 ** </dd> 9028 ** 9029 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 9030 ** <dd>This parameter returns the number of pager cache misses that have 9031 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 9032 ** is always 0. 9033 ** </dd> 9034 ** 9035 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 9036 ** <dd>This parameter returns the number of dirty cache entries that have 9037 ** been written to disk. Specifically, the number of pages written to the 9038 ** wal file in wal mode databases, or the number of pages written to the 9039 ** database file in rollback mode databases. Any pages written as part of 9040 ** transaction rollback or database recovery operations are not included. 9041 ** If an IO or other error occurs while writing a page to disk, the effect 9042 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 9043 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 9044 ** <p> 9045 ** ^(There is overlap between the quantities measured by this parameter 9046 ** (SQLITE_DBSTATUS_CACHE_WRITE) and SQLITE_DBSTATUS_TEMPBUF_SPILL. 9047 ** Resetting one will reduce the other.)^ 9048 ** </dd> 9049 ** 9050 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 9051 ** <dd>This parameter returns the number of dirty cache entries that have 9052 ** been written to disk in the middle of a transaction due to the page 9053 ** cache overflowing. Transactions are more efficient if they are written 9054 ** to disk all at once. When pages spill mid-transaction, that introduces 9055 ** additional overhead. This parameter can be used to help identify 9056 ** inefficiencies that can be resolved by increasing the cache size. 9057 ** </dd> 9058 ** 9059 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 9060 ** <dd>This parameter returns zero for the current value if and only if 9061 ** all foreign key constraints (deferred or immediate) have been 9062 ** resolved.)^ ^The highwater mark is always 0. 9063 ** 9064 ** [[SQLITE_DBSTATUS_TEMPBUF_SPILL] ^(<dt>SQLITE_DBSTATUS_TEMPBUF_SPILL</dt> 9065 ** <dd>^(This parameter returns the number of bytes written to temporary 9066 ** files on disk that could have been kept in memory had sufficient memory 9067 ** been available. This value includes writes to intermediate tables that 9068 ** are part of complex queries, external sorts that spill to disk, and 9069 ** writes to TEMP tables.)^ 9070 ** ^The highwater mark is always 0. 9071 ** <p> 9072 ** ^(There is overlap between the quantities measured by this parameter 9073 ** (SQLITE_DBSTATUS_TEMPBUF_SPILL) and SQLITE_DBSTATUS_CACHE_WRITE. 9074 ** Resetting one will reduce the other.)^ 9075 ** </dd> 9076 ** </dl> 9077 */ 9078 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 9079 #define SQLITE_DBSTATUS_CACHE_USED 1 9080 #define SQLITE_DBSTATUS_SCHEMA_USED 2 9081 #define SQLITE_DBSTATUS_STMT_USED 3 9082 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 9083 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 9084 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 9085 #define SQLITE_DBSTATUS_CACHE_HIT 7 9086 #define SQLITE_DBSTATUS_CACHE_MISS 8 9087 #define SQLITE_DBSTATUS_CACHE_WRITE 9 9088 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 9089 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 9090 #define SQLITE_DBSTATUS_CACHE_SPILL 12 9091 #define SQLITE_DBSTATUS_TEMPBUF_SPILL 13 9092 #define SQLITE_DBSTATUS_MAX 13 /* Largest defined DBSTATUS */ 9093 9094 9095 /* 9096 ** CAPI3REF: Prepared Statement Status 9097 ** METHOD: sqlite3_stmt 9098 ** 9099 ** ^(Each prepared statement maintains various 9100 ** [SQLITE_STMTSTATUS counters] that measure the number 9101 ** of times it has performed specific operations.)^ These counters can 9102 ** be used to monitor the performance characteristics of the prepared 9103 ** statements. For example, if the number of table steps greatly exceeds 9104 ** the number of table searches or result rows, that would tend to indicate 9105 ** that the prepared statement is using a full table scan rather than 9106 ** an index. 9107 ** 9108 ** ^(This interface is used to retrieve and reset counter values from 9109 ** a [prepared statement]. The first argument is the prepared statement 9110 ** object to be interrogated. The second argument 9111 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 9112 ** to be interrogated.)^ 9113 ** ^The current value of the requested counter is returned. 9114 ** ^If the resetFlg is true, then the counter is reset to zero after this 9115 ** interface call returns. 9116 ** 9117 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 9118 */ 9119 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 9120 9121 /* 9122 ** CAPI3REF: Status Parameters for prepared statements 9123 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 9124 ** 9125 ** These preprocessor macros define integer codes that name counter 9126 ** values associated with the [sqlite3_stmt_status()] interface. 9127 ** The meanings of the various counters are as follows: 9128 ** 9129 ** <dl> 9130 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 9131 ** <dd>^This is the number of times that SQLite has stepped forward in 9132 ** a table as part of a full table scan. Large numbers for this counter 9133 ** may indicate opportunities for performance improvement through 9134 ** careful use of indices.</dd> 9135 ** 9136 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 9137 ** <dd>^This is the number of sort operations that have occurred. 9138 ** A non-zero value in this counter may indicate an opportunity to 9139 ** improve performance through careful use of indices.</dd> 9140 ** 9141 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 9142 ** <dd>^This is the number of rows inserted into transient indices that 9143 ** were created automatically in order to help joins run faster. 9144 ** A non-zero value in this counter may indicate an opportunity to 9145 ** improve performance by adding permanent indices that do not 9146 ** need to be reinitialized each time the statement is run.</dd> 9147 ** 9148 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 9149 ** <dd>^This is the number of virtual machine operations executed 9150 ** by the prepared statement if that number is less than or equal 9151 ** to 2147483647. The number of virtual machine operations can be 9152 ** used as a proxy for the total work done by the prepared statement. 9153 ** If the number of virtual machine operations exceeds 2147483647 9154 ** then the value returned by this statement status code is undefined.</dd> 9155 ** 9156 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 9157 ** <dd>^This is the number of times that the prepare statement has been 9158 ** automatically regenerated due to schema changes or changes to 9159 ** [bound parameters] that might affect the query plan.</dd> 9160 ** 9161 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 9162 ** <dd>^This is the number of times that the prepared statement has 9163 ** been run. A single "run" for the purposes of this counter is one 9164 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 9165 ** The counter is incremented on the first [sqlite3_step()] call of each 9166 ** cycle.</dd> 9167 ** 9168 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 9169 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 9170 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 9171 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 9172 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 9173 ** step was bypassed because a Bloom filter returned not-found. The 9174 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 9175 ** times that the Bloom filter returned a find, and thus the join step 9176 ** had to be processed as normal.</dd> 9177 ** 9178 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 9179 ** <dd>^This is the approximate number of bytes of heap memory 9180 ** used to store the prepared statement. ^This value is not actually 9181 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 9182 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 9183 ** </dd> 9184 ** </dl> 9185 */ 9186 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 9187 #define SQLITE_STMTSTATUS_SORT 2 9188 #define SQLITE_STMTSTATUS_AUTOINDEX 3 9189 #define SQLITE_STMTSTATUS_VM_STEP 4 9190 #define SQLITE_STMTSTATUS_REPREPARE 5 9191 #define SQLITE_STMTSTATUS_RUN 6 9192 #define SQLITE_STMTSTATUS_FILTER_MISS 7 9193 #define SQLITE_STMTSTATUS_FILTER_HIT 8 9194 #define SQLITE_STMTSTATUS_MEMUSED 99 9195 9196 /* 9197 ** CAPI3REF: Custom Page Cache Object 9198 ** 9199 ** The sqlite3_pcache type is opaque. It is implemented by 9200 ** the pluggable module. The SQLite core has no knowledge of 9201 ** its size or internal structure and never deals with the 9202 ** sqlite3_pcache object except by holding and passing pointers 9203 ** to the object. 9204 ** 9205 ** See [sqlite3_pcache_methods2] for additional information. 9206 */ 9207 typedef struct sqlite3_pcache sqlite3_pcache; 9208 9209 /* 9210 ** CAPI3REF: Custom Page Cache Object 9211 ** 9212 ** The sqlite3_pcache_page object represents a single page in the 9213 ** page cache. The page cache will allocate instances of this 9214 ** object. Various methods of the page cache use pointers to instances 9215 ** of this object as parameters or as their return value. 9216 ** 9217 ** See [sqlite3_pcache_methods2] for additional information. 9218 */ 9219 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 9220 struct sqlite3_pcache_page { 9221 void *pBuf; /* The content of the page */ 9222 void *pExtra; /* Extra information associated with the page */ 9223 }; 9224 9225 /* 9226 ** CAPI3REF: Application Defined Page Cache. 9227 ** KEYWORDS: {page cache} 9228 ** 9229 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 9230 ** register an alternative page cache implementation by passing in an 9231 ** instance of the sqlite3_pcache_methods2 structure.)^ 9232 ** In many applications, most of the heap memory allocated by 9233 ** SQLite is used for the page cache. 9234 ** By implementing a 9235 ** custom page cache using this API, an application can better control 9236 ** the amount of memory consumed by SQLite, the way in which 9237 ** that memory is allocated and released, and the policies used to 9238 ** determine exactly which parts of a database file are cached and for 9239 ** how long. 9240 ** 9241 ** The alternative page cache mechanism is an 9242 ** extreme measure that is only needed by the most demanding applications. 9243 ** The built-in page cache is recommended for most uses. 9244 ** 9245 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 9246 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 9247 ** the application may discard the parameter after the call to 9248 ** [sqlite3_config()] returns.)^ 9249 ** 9250 ** [[the xInit() page cache method]] 9251 ** ^(The xInit() method is called once for each effective 9252 ** call to [sqlite3_initialize()])^ 9253 ** (usually only once during the lifetime of the process). ^(The xInit() 9254 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 9255 ** The intent of the xInit() method is to set up global data structures 9256 ** required by the custom page cache implementation. 9257 ** ^(If the xInit() method is NULL, then the 9258 ** built-in default page cache is used instead of the application defined 9259 ** page cache.)^ 9260 ** 9261 ** [[the xShutdown() page cache method]] 9262 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 9263 ** It can be used to clean up 9264 ** any outstanding resources before process shutdown, if required. 9265 ** ^The xShutdown() method may be NULL. 9266 ** 9267 ** ^SQLite automatically serializes calls to the xInit method, 9268 ** so the xInit method need not be threadsafe. ^The 9269 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 9270 ** not need to be threadsafe either. All other methods must be threadsafe 9271 ** in multithreaded applications. 9272 ** 9273 ** ^SQLite will never invoke xInit() more than once without an intervening 9274 ** call to xShutdown(). 9275 ** 9276 ** [[the xCreate() page cache methods]] 9277 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 9278 ** SQLite will typically create one cache instance for each open database file, 9279 ** though this is not guaranteed. ^The 9280 ** first parameter, szPage, is the size in bytes of the pages that must 9281 ** be allocated by the cache. ^szPage will always be a power of two. ^The 9282 ** second parameter szExtra is a number of bytes of extra storage 9283 ** associated with each page cache entry. ^The szExtra parameter will be 9284 ** a number less than 250. SQLite will use the 9285 ** extra szExtra bytes on each page to store metadata about the underlying 9286 ** database page on disk. The value passed into szExtra depends 9287 ** on the SQLite version, the target platform, and how SQLite was compiled. 9288 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 9289 ** created will be used to cache database pages of a file stored on disk, or 9290 ** false if it is used for an in-memory database. The cache implementation 9291 ** does not have to do anything special based upon the value of bPurgeable; 9292 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 9293 ** never invoke xUnpin() except to deliberately delete a page. 9294 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 9295 ** false will always have the "discard" flag set to true. 9296 ** ^Hence, a cache created with bPurgeable set to false will 9297 ** never contain any unpinned pages. 9298 ** 9299 ** [[the xCachesize() page cache method]] 9300 ** ^(The xCachesize() method may be called at any time by SQLite to set the 9301 ** suggested maximum cache-size (number of pages stored) for the cache 9302 ** instance passed as the first argument. This is the value configured using 9303 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 9304 ** parameter, the implementation is not required to do anything with this 9305 ** value; it is advisory only. 9306 ** 9307 ** [[the xPagecount() page cache methods]] 9308 ** The xPagecount() method must return the number of pages currently 9309 ** stored in the cache, both pinned and unpinned. 9310 ** 9311 ** [[the xFetch() page cache methods]] 9312 ** The xFetch() method locates a page in the cache and returns a pointer to 9313 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 9314 ** The pBuf element of the returned sqlite3_pcache_page object will be a 9315 ** pointer to a buffer of szPage bytes used to store the content of a 9316 ** single database page. The pExtra element of sqlite3_pcache_page will be 9317 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 9318 ** for each entry in the page cache. 9319 ** 9320 ** The page to be fetched is determined by the key. ^The minimum key value 9321 ** is 1. After it has been retrieved using xFetch, the page is considered 9322 ** to be "pinned". 9323 ** 9324 ** If the requested page is already in the page cache, then the page cache 9325 ** implementation must return a pointer to the page buffer with its content 9326 ** intact. If the requested page is not already in the cache, then the 9327 ** cache implementation should use the value of the createFlag 9328 ** parameter to help it determine what action to take: 9329 ** 9330 ** <table border=1 width=85% align=center> 9331 ** <tr><th> createFlag <th> Behavior when page is not already in cache 9332 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 9333 ** <tr><td> 1 <td> Allocate a new page if it is easy and convenient to do so. 9334 ** Otherwise return NULL. 9335 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 9336 ** NULL if allocating a new page is effectively impossible. 9337 ** </table> 9338 ** 9339 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 9340 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 9341 ** failed.)^ In between the xFetch() calls, SQLite may 9342 ** attempt to unpin one or more cache pages by spilling the content of 9343 ** pinned pages to disk and synching the operating system disk cache. 9344 ** 9345 ** [[the xUnpin() page cache method]] 9346 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 9347 ** as its second argument. If the third parameter, discard, is non-zero, 9348 ** then the page must be evicted from the cache. 9349 ** ^If the discard parameter is 9350 ** zero, then the page may be discarded or retained at the discretion of the 9351 ** page cache implementation. ^The page cache implementation 9352 ** may choose to evict unpinned pages at any time. 9353 ** 9354 ** The cache must not perform any reference counting. A single 9355 ** call to xUnpin() unpins the page regardless of the number of prior calls 9356 ** to xFetch(). 9357 ** 9358 ** [[the xRekey() page cache methods]] 9359 ** The xRekey() method is used to change the key value associated with the 9360 ** page passed as the second argument. If the cache 9361 ** previously contains an entry associated with newKey, it must be 9362 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 9363 ** to be pinned. 9364 ** 9365 ** When SQLite calls the xTruncate() method, the cache must discard all 9366 ** existing cache entries with page numbers (keys) greater than or equal 9367 ** to the value of the iLimit parameter passed to xTruncate(). If any 9368 ** of these pages are pinned, they become implicitly unpinned, meaning that 9369 ** they can be safely discarded. 9370 ** 9371 ** [[the xDestroy() page cache method]] 9372 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 9373 ** All resources associated with the specified cache should be freed. ^After 9374 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 9375 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 9376 ** functions. 9377 ** 9378 ** [[the xShrink() page cache method]] 9379 ** ^SQLite invokes the xShrink() method when it wants the page cache to 9380 ** free up as much of heap memory as possible. The page cache implementation 9381 ** is not obligated to free any memory, but well-behaved implementations should 9382 ** do their best. 9383 */ 9384 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 9385 struct sqlite3_pcache_methods2 { 9386 int iVersion; 9387 void *pArg; 9388 int (*xInit)(void*); 9389 void (*xShutdown)(void*); 9390 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 9391 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9392 int (*xPagecount)(sqlite3_pcache*); 9393 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9394 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 9395 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 9396 unsigned oldKey, unsigned newKey); 9397 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9398 void (*xDestroy)(sqlite3_pcache*); 9399 void (*xShrink)(sqlite3_pcache*); 9400 }; 9401 9402 /* 9403 ** This is the obsolete pcache_methods object that has now been replaced 9404 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 9405 ** retained in the header file for backwards compatibility only. 9406 */ 9407 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 9408 struct sqlite3_pcache_methods { 9409 void *pArg; 9410 int (*xInit)(void*); 9411 void (*xShutdown)(void*); 9412 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 9413 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9414 int (*xPagecount)(sqlite3_pcache*); 9415 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9416 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 9417 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 9418 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9419 void (*xDestroy)(sqlite3_pcache*); 9420 }; 9421 9422 9423 /* 9424 ** CAPI3REF: Online Backup Object 9425 ** 9426 ** The sqlite3_backup object records state information about an ongoing 9427 ** online backup operation. ^The sqlite3_backup object is created by 9428 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 9429 ** [sqlite3_backup_finish()]. 9430 ** 9431 ** See Also: [Using the SQLite Online Backup API] 9432 */ 9433 typedef struct sqlite3_backup sqlite3_backup; 9434 9435 /* 9436 ** CAPI3REF: Online Backup API. 9437 ** 9438 ** The backup API copies the content of one database into another. 9439 ** It is useful either for creating backups of databases or 9440 ** for copying in-memory databases to or from persistent files. 9441 ** 9442 ** See Also: [Using the SQLite Online Backup API] 9443 ** 9444 ** ^SQLite holds a write transaction open on the destination database file 9445 ** for the duration of the backup operation. 9446 ** ^The source database is read-locked only while it is being read; 9447 ** it is not locked continuously for the entire backup operation. 9448 ** ^Thus, the backup may be performed on a live source database without 9449 ** preventing other database connections from 9450 ** reading or writing to the source database while the backup is underway. 9451 ** 9452 ** ^(To perform a backup operation: 9453 ** <ol> 9454 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 9455 ** backup, 9456 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 9457 ** the data between the two databases, and finally 9458 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 9459 ** associated with the backup operation. 9460 ** </ol>)^ 9461 ** There should be exactly one call to sqlite3_backup_finish() for each 9462 ** successful call to sqlite3_backup_init(). 9463 ** 9464 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 9465 ** 9466 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 9467 ** [database connection] associated with the destination database 9468 ** and the database name, respectively. 9469 ** ^The database name is "main" for the main database, "temp" for the 9470 ** temporary database, or the name specified after the AS keyword in 9471 ** an [ATTACH] statement for an attached database. 9472 ** ^The S and M arguments passed to 9473 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 9474 ** and database name of the source database, respectively. 9475 ** ^The source and destination [database connections] (parameters S and D) 9476 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 9477 ** an error. 9478 ** 9479 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 9480 ** there is already a read or read-write transaction open on the 9481 ** destination database. 9482 ** 9483 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 9484 ** returned and an error code and error message are stored in the 9485 ** destination [database connection] D. 9486 ** ^The error code and message for the failed call to sqlite3_backup_init() 9487 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 9488 ** [sqlite3_errmsg16()] functions. 9489 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 9490 ** [sqlite3_backup] object. 9491 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 9492 ** sqlite3_backup_finish() functions to perform the specified backup 9493 ** operation. 9494 ** 9495 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 9496 ** 9497 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 9498 ** the source and destination databases specified by [sqlite3_backup] object B. 9499 ** ^If N is negative, all remaining source pages are copied. 9500 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 9501 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 9502 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 9503 ** from source to destination, then it returns [SQLITE_DONE]. 9504 ** ^If an error occurs while running sqlite3_backup_step(B,N), 9505 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 9506 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 9507 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 9508 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 9509 ** 9510 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 9511 ** <ol> 9512 ** <li> the destination database was opened read-only, or 9513 ** <li> the destination database is using write-ahead-log journaling 9514 ** and the destination and source page sizes differ, or 9515 ** <li> the destination database is an in-memory database and the 9516 ** destination and source page sizes differ. 9517 ** </ol>)^ 9518 ** 9519 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 9520 ** the [sqlite3_busy_handler | busy-handler function] 9521 ** is invoked (if one is specified). ^If the 9522 ** busy-handler returns non-zero before the lock is available, then 9523 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 9524 ** sqlite3_backup_step() can be retried later. ^If the source 9525 ** [database connection] 9526 ** is being used to write to the source database when sqlite3_backup_step() 9527 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 9528 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 9529 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 9530 ** [SQLITE_READONLY] is returned, then 9531 ** there is no point in retrying the call to sqlite3_backup_step(). These 9532 ** errors are considered fatal.)^ The application must accept 9533 ** that the backup operation has failed and pass the backup operation handle 9534 ** to the sqlite3_backup_finish() to release associated resources. 9535 ** 9536 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 9537 ** on the destination file. ^The exclusive lock is not released until either 9538 ** sqlite3_backup_finish() is called or the backup operation is complete 9539 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 9540 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 9541 ** lasts for the duration of the sqlite3_backup_step() call. 9542 ** ^Because the source database is not locked between calls to 9543 ** sqlite3_backup_step(), the source database may be modified mid-way 9544 ** through the backup process. ^If the source database is modified by an 9545 ** external process or via a database connection other than the one being 9546 ** used by the backup operation, then the backup will be automatically 9547 ** restarted by the next call to sqlite3_backup_step(). ^If the source 9548 ** database is modified by using the same database connection as is used 9549 ** by the backup operation, then the backup database is automatically 9550 ** updated at the same time. 9551 ** 9552 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 9553 ** 9554 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 9555 ** application wishes to abandon the backup operation, the application 9556 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 9557 ** ^The sqlite3_backup_finish() interfaces releases all 9558 ** resources associated with the [sqlite3_backup] object. 9559 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 9560 ** active write-transaction on the destination database is rolled back. 9561 ** The [sqlite3_backup] object is invalid 9562 ** and may not be used following a call to sqlite3_backup_finish(). 9563 ** 9564 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 9565 ** sqlite3_backup_step() errors occurred, regardless of whether or not 9566 ** sqlite3_backup_step() completed. 9567 ** ^If an out-of-memory condition or IO error occurred during any prior 9568 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 9569 ** sqlite3_backup_finish() returns the corresponding [error code]. 9570 ** 9571 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9572 ** is not a permanent error and does not affect the return value of 9573 ** sqlite3_backup_finish(). 9574 ** 9575 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9576 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9577 ** 9578 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 9579 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9580 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9581 ** in the source database at the conclusion of the most recent 9582 ** sqlite3_backup_step(). 9583 ** ^(The values returned by these functions are only updated by 9584 ** sqlite3_backup_step(). If the source database is modified in a way that 9585 ** changes the size of the source database or the number of pages remaining, 9586 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 9587 ** and sqlite3_backup_remaining() until after the next 9588 ** sqlite3_backup_step().)^ 9589 ** 9590 ** <b>Concurrent Usage of Database Handles</b> 9591 ** 9592 ** ^The source [database connection] may be used by the application for other 9593 ** purposes while a backup operation is underway or being initialized. 9594 ** ^If SQLite is compiled and configured to support threadsafe database 9595 ** connections, then the source database connection may be used concurrently 9596 ** from within other threads. 9597 ** 9598 ** However, the application must guarantee that the destination 9599 ** [database connection] is not passed to any other API (by any thread) after 9600 ** sqlite3_backup_init() is called and before the corresponding call to 9601 ** sqlite3_backup_finish(). SQLite does not currently check to see 9602 ** if the application incorrectly accesses the destination [database connection] 9603 ** and so no error code is reported, but the operations may malfunction 9604 ** nevertheless. Use of the destination database connection while a 9605 ** backup is in progress might also cause a mutex deadlock. 9606 ** 9607 ** If running in [shared cache mode], the application must 9608 ** guarantee that the shared cache used by the destination database 9609 ** is not accessed while the backup is running. In practice this means 9610 ** that the application must guarantee that the disk file being 9611 ** backed up to is not accessed by any connection within the process, 9612 ** not just the specific connection that was passed to sqlite3_backup_init(). 9613 ** 9614 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9615 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9616 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9617 ** APIs are not strictly speaking threadsafe. If they are invoked at the 9618 ** same time as another thread is invoking sqlite3_backup_step() it is 9619 ** possible that they return invalid values. 9620 ** 9621 ** <b>Alternatives To Using The Backup API</b> 9622 ** 9623 ** Other techniques for safely creating a consistent backup of an SQLite 9624 ** database include: 9625 ** 9626 ** <ul> 9627 ** <li> The [VACUUM INTO] command. 9628 ** <li> The [sqlite3_rsync] utility program. 9629 ** </ul> 9630 */ 9631 SQLITE_API sqlite3_backup *sqlite3_backup_init( 9632 sqlite3 *pDest, /* Destination database handle */ 9633 const char *zDestName, /* Destination database name */ 9634 sqlite3 *pSource, /* Source database handle */ 9635 const char *zSourceName /* Source database name */ 9636 ); 9637 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9638 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9639 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9640 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9641 9642 /* 9643 ** CAPI3REF: Unlock Notification 9644 ** METHOD: sqlite3 9645 ** 9646 ** ^When running in shared-cache mode, a database operation may fail with 9647 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9648 ** individual tables within the shared-cache cannot be obtained. See 9649 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9650 ** ^This API may be used to register a callback that SQLite will invoke 9651 ** when the connection currently holding the required lock relinquishes it. 9652 ** ^This API is only available if the library was compiled with the 9653 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9654 ** 9655 ** See Also: [Using the SQLite Unlock Notification Feature]. 9656 ** 9657 ** ^Shared-cache locks are released when a database connection concludes 9658 ** its current transaction, either by committing it or rolling it back. 9659 ** 9660 ** ^When a connection (known as the blocked connection) fails to obtain a 9661 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9662 ** identity of the database connection (the blocking connection) that 9663 ** has locked the required resource is stored internally. ^After an 9664 ** application receives an SQLITE_LOCKED error, it may call the 9665 ** sqlite3_unlock_notify() method with the blocked connection handle as 9666 ** the first argument to register for a callback that will be invoked 9667 ** when the blocking connection's current transaction is concluded. ^The 9668 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9669 ** call that concludes the blocking connection's transaction. 9670 ** 9671 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9672 ** there is a chance that the blocking connection will have already 9673 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9674 ** If this happens, then the specified callback is invoked immediately, 9675 ** from within the call to sqlite3_unlock_notify().)^ 9676 ** 9677 ** ^If the blocked connection is attempting to obtain a write-lock on a 9678 ** shared-cache table, and more than one other connection currently holds 9679 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9680 ** the other connections to use as the blocking connection. 9681 ** 9682 ** ^(There may be at most one unlock-notify callback registered by a 9683 ** blocked connection. If sqlite3_unlock_notify() is called when the 9684 ** blocked connection already has a registered unlock-notify callback, 9685 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9686 ** called with a NULL pointer as its second argument, then any existing 9687 ** unlock-notify callback is canceled. ^The blocked connection's 9688 ** unlock-notify callback may also be canceled by closing the blocked 9689 ** connection using [sqlite3_close()]. 9690 ** 9691 ** The unlock-notify callback is not reentrant. If an application invokes 9692 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9693 ** crash or deadlock may be the result. 9694 ** 9695 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9696 ** returns SQLITE_OK. 9697 ** 9698 ** <b>Callback Invocation Details</b> 9699 ** 9700 ** When an unlock-notify callback is registered, the application provides a 9701 ** single void* pointer that is passed to the callback when it is invoked. 9702 ** However, the signature of the callback function allows SQLite to pass 9703 ** it an array of void* context pointers. The first argument passed to 9704 ** an unlock-notify callback is a pointer to an array of void* pointers, 9705 ** and the second is the number of entries in the array. 9706 ** 9707 ** When a blocking connection's transaction is concluded, there may be 9708 ** more than one blocked connection that has registered for an unlock-notify 9709 ** callback. ^If two or more such blocked connections have specified the 9710 ** same callback function, then instead of invoking the callback function 9711 ** multiple times, it is invoked once with the set of void* context pointers 9712 ** specified by the blocked connections bundled together into an array. 9713 ** This gives the application an opportunity to prioritize any actions 9714 ** related to the set of unblocked database connections. 9715 ** 9716 ** <b>Deadlock Detection</b> 9717 ** 9718 ** Assuming that after registering for an unlock-notify callback a 9719 ** database waits for the callback to be issued before taking any further 9720 ** action (a reasonable assumption), then using this API may cause the 9721 ** application to deadlock. For example, if connection X is waiting for 9722 ** connection Y's transaction to be concluded, and similarly connection 9723 ** Y is waiting on connection X's transaction, then neither connection 9724 ** will proceed and the system may remain deadlocked indefinitely. 9725 ** 9726 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9727 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9728 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9729 ** unlock-notify callback is registered. The system is said to be in 9730 ** a deadlocked state if connection A has registered for an unlock-notify 9731 ** callback on the conclusion of connection B's transaction, and connection 9732 ** B has itself registered for an unlock-notify callback when connection 9733 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9734 ** the system is also considered to be deadlocked if connection B has 9735 ** registered for an unlock-notify callback on the conclusion of connection 9736 ** C's transaction, where connection C is waiting on connection A. ^Any 9737 ** number of levels of indirection are allowed. 9738 ** 9739 ** <b>The "DROP TABLE" Exception</b> 9740 ** 9741 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9742 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9743 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9744 ** SQLite checks if there are any currently executing SELECT statements 9745 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9746 ** returned. In this case there is no "blocking connection", so invoking 9747 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9748 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9749 ** or "DROP INDEX" query, an infinite loop might be the result. 9750 ** 9751 ** One way around this problem is to check the extended error code returned 9752 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9753 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9754 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9755 ** SQLITE_LOCKED.)^ 9756 */ 9757 SQLITE_API int sqlite3_unlock_notify( 9758 sqlite3 *pBlocked, /* Waiting connection */ 9759 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9760 void *pNotifyArg /* Argument to pass to xNotify */ 9761 ); 9762 9763 9764 /* 9765 ** CAPI3REF: String Comparison 9766 ** 9767 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9768 ** and extensions to compare the contents of two buffers containing UTF-8 9769 ** strings in a case-independent fashion, using the same definition of "case 9770 ** independence" that SQLite uses internally when comparing identifiers. 9771 */ 9772 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9773 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9774 9775 /* 9776 ** CAPI3REF: String Globbing 9777 * 9778 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9779 ** string X matches the [GLOB] pattern P. 9780 ** ^The definition of [GLOB] pattern matching used in 9781 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9782 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9783 ** is case sensitive. 9784 ** 9785 ** Note that this routine returns zero on a match and non-zero if the strings 9786 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9787 ** 9788 ** See also: [sqlite3_strlike()]. 9789 */ 9790 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9791 9792 /* 9793 ** CAPI3REF: String LIKE Matching 9794 * 9795 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9796 ** string X matches the [LIKE] pattern P with escape character E. 9797 ** ^The definition of [LIKE] pattern matching used in 9798 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9799 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9800 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9801 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9802 ** insensitive - equivalent upper and lower case ASCII characters match 9803 ** one another. 9804 ** 9805 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9806 ** only ASCII characters are case folded. 9807 ** 9808 ** Note that this routine returns zero on a match and non-zero if the strings 9809 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9810 ** 9811 ** See also: [sqlite3_strglob()]. 9812 */ 9813 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9814 9815 /* 9816 ** CAPI3REF: Error Logging Interface 9817 ** 9818 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9819 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9820 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9821 ** used with [sqlite3_snprintf()] to generate the final output string. 9822 ** 9823 ** The sqlite3_log() interface is intended for use by extensions such as 9824 ** virtual tables, collating functions, and SQL functions. While there is 9825 ** nothing to prevent an application from calling sqlite3_log(), doing so 9826 ** is considered bad form. 9827 ** 9828 ** The zFormat string must not be NULL. 9829 ** 9830 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9831 ** will not use dynamically allocated memory. The log message is stored in 9832 ** a fixed-length buffer on the stack. If the log message is longer than 9833 ** a few hundred characters, it will be truncated to the length of the 9834 ** buffer. 9835 */ 9836 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9837 9838 /* 9839 ** CAPI3REF: Write-Ahead Log Commit Hook 9840 ** METHOD: sqlite3 9841 ** 9842 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9843 ** is invoked each time data is committed to a database in wal mode. 9844 ** 9845 ** ^(The callback is invoked by SQLite after the commit has taken place and 9846 ** the associated write-lock on the database released)^, so the implementation 9847 ** may read, write or [checkpoint] the database as required. 9848 ** 9849 ** ^The first parameter passed to the callback function when it is invoked 9850 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9851 ** registering the callback. ^The second is a copy of the database handle. 9852 ** ^The third parameter is the name of the database that was written to - 9853 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9854 ** is the number of pages currently in the write-ahead log file, 9855 ** including those that were just committed. 9856 ** 9857 ** ^The callback function should normally return [SQLITE_OK]. ^If an error 9858 ** code is returned, that error will propagate back up through the 9859 ** SQLite code base to cause the statement that provoked the callback 9860 ** to report an error, though the commit will have still occurred. If the 9861 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9862 ** that does not correspond to any valid SQLite error code, the results 9863 ** are undefined. 9864 ** 9865 ** ^A single database handle may have at most a single write-ahead log 9866 ** callback registered at one time. ^Calling [sqlite3_wal_hook()] 9867 ** replaces the default behavior or previously registered write-ahead 9868 ** log callback. 9869 ** 9870 ** ^The return value is a copy of the third parameter from the 9871 ** previous call, if any, or 0. 9872 ** 9873 ** ^The [sqlite3_wal_autocheckpoint()] interface and the 9874 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and 9875 ** will overwrite any prior [sqlite3_wal_hook()] settings. 9876 ** 9877 ** ^If a write-ahead log callback is set using this function then 9878 ** [sqlite3_wal_checkpoint_v2()] or [PRAGMA wal_checkpoint] 9879 ** should be invoked periodically to keep the write-ahead log file 9880 ** from growing without bound. 9881 ** 9882 ** ^Passing a NULL pointer for the callback disables automatic 9883 ** checkpointing entirely. To re-enable the default behavior, call 9884 ** sqlite3_wal_autocheckpoint(db,1000) or use [PRAGMA wal_checkpoint]. 9885 */ 9886 SQLITE_API void *sqlite3_wal_hook( 9887 sqlite3*, 9888 int(*)(void *,sqlite3*,const char*,int), 9889 void* 9890 ); 9891 9892 /* 9893 ** CAPI3REF: Configure an auto-checkpoint 9894 ** METHOD: sqlite3 9895 ** 9896 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9897 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9898 ** to automatically [checkpoint] 9899 ** after committing a transaction if there are N or 9900 ** more frames in the [write-ahead log] file. ^Passing zero or 9901 ** a negative value as the N parameter disables automatic 9902 ** checkpoints entirely. 9903 ** 9904 ** ^The callback registered by this function replaces any existing callback 9905 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9906 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9907 ** configured by this function. 9908 ** 9909 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9910 ** from SQL. 9911 ** 9912 ** ^Checkpoints initiated by this mechanism are 9913 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9914 ** 9915 ** ^Every new [database connection] defaults to having the auto-checkpoint 9916 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9917 ** pages. 9918 ** 9919 ** ^The use of this interface is only necessary if the default setting 9920 ** is found to be suboptimal for a particular application. 9921 */ 9922 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9923 9924 /* 9925 ** CAPI3REF: Checkpoint a database 9926 ** METHOD: sqlite3 9927 ** 9928 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9929 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9930 ** 9931 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9932 ** [write-ahead log] for database X on [database connection] D to be 9933 ** transferred into the database file and for the write-ahead log to 9934 ** be reset. See the [checkpointing] documentation for addition 9935 ** information. 9936 ** 9937 ** This interface used to be the only way to cause a checkpoint to 9938 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9939 ** interface was added. This interface is retained for backwards 9940 ** compatibility and as a convenience for applications that need to manually 9941 ** start a callback but which do not need the full power (and corresponding 9942 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9943 */ 9944 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9945 9946 /* 9947 ** CAPI3REF: Checkpoint a database 9948 ** METHOD: sqlite3 9949 ** 9950 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9951 ** operation on database X of [database connection] D in mode M. Status 9952 ** information is written back into integers pointed to by L and C.)^ 9953 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9954 ** 9955 ** <dl> 9956 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9957 ** ^Checkpoint as many frames as possible without waiting for any database 9958 ** readers or writers to finish, then sync the database file if all frames 9959 ** in the log were checkpointed. ^The [busy-handler callback] 9960 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9961 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9962 ** if there are concurrent readers or writers. 9963 ** 9964 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9965 ** ^This mode blocks (it invokes the 9966 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9967 ** database writer and all readers are reading from the most recent database 9968 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9969 ** database file. ^This mode blocks new database writers while it is pending, 9970 ** but new database readers are allowed to continue unimpeded. 9971 ** 9972 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9973 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9974 ** that after checkpointing the log file it blocks (calls the 9975 ** [busy-handler callback]) 9976 ** until all readers are reading from the database file only. ^This ensures 9977 ** that the next writer will restart the log file from the beginning. 9978 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9979 ** database writer attempts while it is pending, but does not impede readers. 9980 ** 9981 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9982 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9983 ** addition that it also truncates the log file to zero bytes just prior 9984 ** to a successful return. 9985 ** 9986 ** <dt>SQLITE_CHECKPOINT_NOOP<dd> 9987 ** ^This mode always checkpoints zero frames. The only reason to invoke 9988 ** a NOOP checkpoint is to access the values returned by 9989 ** sqlite3_wal_checkpoint_v2() via output parameters *pnLog and *pnCkpt. 9990 ** </dl> 9991 ** 9992 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9993 ** the log file or to -1 if the checkpoint could not run because 9994 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9995 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9996 ** log file (including any that were already checkpointed before the function 9997 ** was called) or to -1 if the checkpoint could not run due to an error or 9998 ** because the database is not in WAL mode. ^Note that upon successful 9999 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 10000 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 10001 ** 10002 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 10003 ** any other process is running a checkpoint operation at the same time, the 10004 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 10005 ** busy-handler configured, it will not be invoked in this case. 10006 ** 10007 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 10008 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 10009 ** obtained immediately, and a busy-handler is configured, it is invoked and 10010 ** the writer lock retried until either the busy-handler returns 0 or the lock 10011 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 10012 ** database readers as described above. ^If the busy-handler returns 0 before 10013 ** the writer lock is obtained or while waiting for database readers, the 10014 ** checkpoint operation proceeds from that point in the same way as 10015 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 10016 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 10017 ** 10018 ** ^If parameter zDb is NULL or points to a zero length string, then the 10019 ** specified operation is attempted on all WAL databases [attached] to 10020 ** [database connection] db. In this case the 10021 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 10022 ** an SQLITE_BUSY error is encountered when processing one or more of the 10023 ** attached WAL databases, the operation is still attempted on any remaining 10024 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 10025 ** error occurs while processing an attached database, processing is abandoned 10026 ** and the error code is returned to the caller immediately. ^If no error 10027 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 10028 ** databases, SQLITE_OK is returned. 10029 ** 10030 ** ^If database zDb is the name of an attached database that is not in WAL 10031 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 10032 ** zDb is not NULL (or a zero length string) and is not the name of any 10033 ** attached database, SQLITE_ERROR is returned to the caller. 10034 ** 10035 ** ^Unless it returns SQLITE_MISUSE, 10036 ** the sqlite3_wal_checkpoint_v2() interface 10037 ** sets the error information that is queried by 10038 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 10039 ** 10040 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 10041 ** from SQL. 10042 */ 10043 SQLITE_API int sqlite3_wal_checkpoint_v2( 10044 sqlite3 *db, /* Database handle */ 10045 const char *zDb, /* Name of attached database (or NULL) */ 10046 int eMode, /* SQLITE_CHECKPOINT_* value */ 10047 int *pnLog, /* OUT: Size of WAL log in frames */ 10048 int *pnCkpt /* OUT: Total number of frames checkpointed */ 10049 ); 10050 10051 /* 10052 ** CAPI3REF: Checkpoint Mode Values 10053 ** KEYWORDS: {checkpoint mode} 10054 ** 10055 ** These constants define all valid values for the "checkpoint mode" passed 10056 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 10057 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 10058 ** meaning of each of these checkpoint modes. 10059 */ 10060 #define SQLITE_CHECKPOINT_NOOP -1 /* Do no work at all */ 10061 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 10062 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 10063 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 10064 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 10065 10066 /* 10067 ** CAPI3REF: Virtual Table Interface Configuration 10068 ** 10069 ** This function may be called by either the [xConnect] or [xCreate] method 10070 ** of a [virtual table] implementation to configure 10071 ** various facets of the virtual table interface. 10072 ** 10073 ** If this interface is invoked outside the context of an xConnect or 10074 ** xCreate virtual table method then the behavior is undefined. 10075 ** 10076 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 10077 ** [database connection] in which the virtual table is being created and 10078 ** which is passed in as the first argument to the [xConnect] or [xCreate] 10079 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 10080 ** of the [virtual table configuration options]. The presence and meaning 10081 ** of parameters after C depend on which [virtual table configuration option] 10082 ** is used. 10083 */ 10084 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 10085 10086 /* 10087 ** CAPI3REF: Virtual Table Configuration Options 10088 ** KEYWORDS: {virtual table configuration options} 10089 ** KEYWORDS: {virtual table configuration option} 10090 ** 10091 ** These macros define the various options to the 10092 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 10093 ** can use to customize and optimize their behavior. 10094 ** 10095 ** <dl> 10096 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 10097 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 10098 ** <dd>Calls of the form 10099 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 10100 ** where X is an integer. If X is zero, then the [virtual table] whose 10101 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 10102 ** support constraints. In this configuration (which is the default) if 10103 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 10104 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 10105 ** specified as part of the user's SQL statement, regardless of the actual 10106 ** ON CONFLICT mode specified. 10107 ** 10108 ** If X is non-zero, then the virtual table implementation guarantees 10109 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 10110 ** any modifications to internal or persistent data structures have been made. 10111 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 10112 ** is able to roll back a statement or database transaction, and abandon 10113 ** or continue processing the current SQL statement as appropriate. 10114 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 10115 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 10116 ** had been ABORT. 10117 ** 10118 ** Virtual table implementations that are required to handle OR REPLACE 10119 ** must do so within the [xUpdate] method. If a call to the 10120 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 10121 ** CONFLICT policy is REPLACE, the virtual table implementation should 10122 ** silently replace the appropriate rows within the xUpdate callback and 10123 ** return SQLITE_OK. Or, if this is not possible, it may return 10124 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 10125 ** constraint handling. 10126 ** </dd> 10127 ** 10128 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 10129 ** <dd>Calls of the form 10130 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 10131 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 10132 ** prohibits that virtual table from being used from within triggers and 10133 ** views. 10134 ** </dd> 10135 ** 10136 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 10137 ** <dd>Calls of the form 10138 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 10139 ** [xConnect] or [xCreate] methods of a [virtual table] implementation 10140 ** identify that virtual table as being safe to use from within triggers 10141 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 10142 ** virtual table can do no serious harm even if it is controlled by a 10143 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 10144 ** flag unless absolutely necessary. 10145 ** </dd> 10146 ** 10147 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt> 10148 ** <dd>Calls of the form 10149 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the 10150 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 10151 ** instruct the query planner to begin at least a read transaction on 10152 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the 10153 ** virtual table is used. 10154 ** </dd> 10155 ** </dl> 10156 */ 10157 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 10158 #define SQLITE_VTAB_INNOCUOUS 2 10159 #define SQLITE_VTAB_DIRECTONLY 3 10160 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4 10161 10162 /* 10163 ** CAPI3REF: Determine The Virtual Table Conflict Policy 10164 ** 10165 ** This function may only be called from within a call to the [xUpdate] method 10166 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 10167 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 10168 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 10169 ** of the SQL statement that triggered the call to the [xUpdate] method of the 10170 ** [virtual table]. 10171 */ 10172 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 10173 10174 /* 10175 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 10176 ** 10177 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 10178 ** method of a [virtual table], then it might return true if the 10179 ** column is being fetched as part of an UPDATE operation during which the 10180 ** column value will not change. The virtual table implementation can use 10181 ** this hint as permission to substitute a return value that is less 10182 ** expensive to compute and that the corresponding 10183 ** [xUpdate] method understands as a "no-change" value. 10184 ** 10185 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 10186 ** the column is not changed by the UPDATE statement, then the xColumn 10187 ** method can optionally return without setting a result, without calling 10188 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 10189 ** In that case, [sqlite3_value_nochange(X)] will return true for the 10190 ** same column in the [xUpdate] method. 10191 ** 10192 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 10193 ** implementations should continue to give a correct answer even if the 10194 ** sqlite3_vtab_nochange() interface were to always return false. In the 10195 ** current implementation, the sqlite3_vtab_nochange() interface does always 10196 ** returns false for the enhanced [UPDATE FROM] statement. 10197 */ 10198 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 10199 10200 /* 10201 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 10202 ** METHOD: sqlite3_index_info 10203 ** 10204 ** This function may only be called from within a call to the [xBestIndex] 10205 ** method of a [virtual table]. This function returns a pointer to a string 10206 ** that is the name of the appropriate collation sequence to use for text 10207 ** comparisons on the constraint identified by its arguments. 10208 ** 10209 ** The first argument must be the pointer to the [sqlite3_index_info] object 10210 ** that is the first parameter to the xBestIndex() method. The second argument 10211 ** must be an index into the aConstraint[] array belonging to the 10212 ** sqlite3_index_info structure passed to xBestIndex. 10213 ** 10214 ** Important: 10215 ** The first parameter must be the same pointer that is passed into the 10216 ** xBestMethod() method. The first parameter may not be a pointer to a 10217 ** different [sqlite3_index_info] object, even an exact copy. 10218 ** 10219 ** The return value is computed as follows: 10220 ** 10221 ** <ol> 10222 ** <li><p> If the constraint comes from a WHERE clause expression that contains 10223 ** a [COLLATE operator], then the name of the collation specified by 10224 ** that COLLATE operator is returned. 10225 ** <li><p> If there is no COLLATE operator, but the column that is the subject 10226 ** of the constraint specifies an alternative collating sequence via 10227 ** a [COLLATE clause] on the column definition within the CREATE TABLE 10228 ** statement that was passed into [sqlite3_declare_vtab()], then the 10229 ** name of that alternative collating sequence is returned. 10230 ** <li><p> Otherwise, "BINARY" is returned. 10231 ** </ol> 10232 */ 10233 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 10234 10235 /* 10236 ** CAPI3REF: Determine if a virtual table query is DISTINCT 10237 ** METHOD: sqlite3_index_info 10238 ** 10239 ** This API may only be used from within an [xBestIndex|xBestIndex method] 10240 ** of a [virtual table] implementation. The result of calling this 10241 ** interface from outside of xBestIndex() is undefined and probably harmful. 10242 ** 10243 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 10244 ** 3. The integer returned by sqlite3_vtab_distinct() 10245 ** gives the virtual table additional information about how the query 10246 ** planner wants the output to be ordered. As long as the virtual table 10247 ** can meet the ordering requirements of the query planner, it may set 10248 ** the "orderByConsumed" flag. 10249 ** 10250 ** <ol><li value="0"><p> 10251 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 10252 ** that the query planner needs the virtual table to return all rows in the 10253 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 10254 ** [sqlite3_index_info] object. This is the default expectation. If the 10255 ** virtual table outputs all rows in sorted order, then it is always safe for 10256 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 10257 ** the return value from sqlite3_vtab_distinct(). 10258 ** <li value="1"><p> 10259 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 10260 ** that the query planner does not need the rows to be returned in sorted order 10261 ** as long as all rows with the same values in all columns identified by the 10262 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 10263 ** is doing a GROUP BY. 10264 ** <li value="2"><p> 10265 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 10266 ** that the query planner does not need the rows returned in any particular 10267 ** order, as long as rows with the same values in all columns identified 10268 ** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows 10269 ** contain the same values for all columns identified by "colUsed", all but 10270 ** one such row may optionally be omitted from the result.)^ 10271 ** The virtual table is not required to omit rows that are duplicates 10272 ** over the "colUsed" columns, but if the virtual table can do that without 10273 ** too much extra effort, it could potentially help the query to run faster. 10274 ** This mode is used for a DISTINCT query. 10275 ** <li value="3"><p> 10276 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the 10277 ** virtual table must return rows in the order defined by "aOrderBy" as 10278 ** if the sqlite3_vtab_distinct() interface had returned 0. However if 10279 ** two or more rows in the result have the same values for all columns 10280 ** identified by "colUsed", then all but one such row may optionally be 10281 ** omitted.)^ Like when the return value is 2, the virtual table 10282 ** is not required to omit rows that are duplicates over the "colUsed" 10283 ** columns, but if the virtual table can do that without 10284 ** too much extra effort, it could potentially help the query to run faster. 10285 ** This mode is used for queries 10286 ** that have both DISTINCT and ORDER BY clauses. 10287 ** </ol> 10288 ** 10289 ** <p>The following table summarizes the conditions under which the 10290 ** virtual table is allowed to set the "orderByConsumed" flag based on 10291 ** the value returned by sqlite3_vtab_distinct(). This table is a 10292 ** restatement of the previous four paragraphs: 10293 ** 10294 ** <table border=1 cellspacing=0 cellpadding=10 width="90%"> 10295 ** <tr> 10296 ** <td valign="top">sqlite3_vtab_distinct() return value 10297 ** <td valign="top">Rows are returned in aOrderBy order 10298 ** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent 10299 ** <td valign="top">Duplicates over all colUsed columns may be omitted 10300 ** <tr><td>0<td>yes<td>yes<td>no 10301 ** <tr><td>1<td>no<td>yes<td>no 10302 ** <tr><td>2<td>no<td>yes<td>yes 10303 ** <tr><td>3<td>yes<td>yes<td>yes 10304 ** </table> 10305 ** 10306 ** ^For the purposes of comparing virtual table output values to see if the 10307 ** values are the same value for sorting purposes, two NULL values are considered 10308 ** to be the same. In other words, the comparison operator is "IS" 10309 ** (or "IS NOT DISTINCT FROM") and not "==". 10310 ** 10311 ** If a virtual table implementation is unable to meet the requirements 10312 ** specified above, then it must not set the "orderByConsumed" flag in the 10313 ** [sqlite3_index_info] object or an incorrect answer may result. 10314 ** 10315 ** ^A virtual table implementation is always free to return rows in any order 10316 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 10317 ** "orderByConsumed" flag is unset, the query planner will add extra 10318 ** [bytecode] to ensure that the final results returned by the SQL query are 10319 ** ordered correctly. The use of the "orderByConsumed" flag and the 10320 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 10321 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 10322 ** flag might help queries against a virtual table to run faster. Being 10323 ** overly aggressive and setting the "orderByConsumed" flag when it is not 10324 ** valid to do so, on the other hand, might cause SQLite to return incorrect 10325 ** results. 10326 */ 10327 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 10328 10329 /* 10330 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 10331 ** 10332 ** This interface may only be used from within an 10333 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 10334 ** The result of invoking this interface from any other context is 10335 ** undefined and probably harmful. 10336 ** 10337 ** ^(A constraint on a virtual table of the form 10338 ** "[IN operator|column IN (...)]" is 10339 ** communicated to the xBestIndex method as a 10340 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 10341 ** this constraint, it must set the corresponding 10342 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under 10343 ** the usual mode of handling IN operators, SQLite generates [bytecode] 10344 ** that invokes the [xFilter|xFilter() method] once for each value 10345 ** on the right-hand side of the IN operator.)^ Thus the virtual table 10346 ** only sees a single value from the right-hand side of the IN operator 10347 ** at a time. 10348 ** 10349 ** In some cases, however, it would be advantageous for the virtual 10350 ** table to see all values on the right-hand of the IN operator all at 10351 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 10352 ** 10353 ** <ol> 10354 ** <li><p> 10355 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 10356 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 10357 ** is an [IN operator] that can be processed all at once. ^In other words, 10358 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 10359 ** by which the virtual table can ask SQLite if all-at-once processing 10360 ** of the IN operator is even possible. 10361 ** 10362 ** <li><p> 10363 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 10364 ** to SQLite that the virtual table does or does not want to process 10365 ** the IN operator all-at-once, respectively. ^Thus when the third 10366 ** parameter (F) is non-negative, this interface is the mechanism by 10367 ** which the virtual table tells SQLite how it wants to process the 10368 ** IN operator. 10369 ** </ol> 10370 ** 10371 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 10372 ** within the same xBestIndex method call. ^For any given P,N pair, 10373 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 10374 ** within the same xBestIndex call. ^If the interface returns true 10375 ** (non-zero), that means that the constraint is an IN operator 10376 ** that can be processed all-at-once. ^If the constraint is not an IN 10377 ** operator or cannot be processed all-at-once, then the interface returns 10378 ** false. 10379 ** 10380 ** ^(All-at-once processing of the IN operator is selected if both of the 10381 ** following conditions are met: 10382 ** 10383 ** <ol> 10384 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 10385 ** integer. This is how the virtual table tells SQLite that it wants to 10386 ** use the N-th constraint. 10387 ** 10388 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 10389 ** non-negative had F>=1. 10390 ** </ol>)^ 10391 ** 10392 ** ^If either or both of the conditions above are false, then SQLite uses 10393 ** the traditional one-at-a-time processing strategy for the IN constraint. 10394 ** ^If both conditions are true, then the argvIndex-th parameter to the 10395 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 10396 ** but which can be passed to [sqlite3_vtab_in_first()] and 10397 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 10398 ** of the IN constraint. 10399 */ 10400 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 10401 10402 /* 10403 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 10404 ** 10405 ** These interfaces are only useful from within the 10406 ** [xFilter|xFilter() method] of a [virtual table] implementation. 10407 ** The result of invoking these interfaces from any other context 10408 ** is undefined and probably harmful. 10409 ** 10410 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 10411 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the 10412 ** xFilter method which invokes these routines, and specifically 10413 ** a parameter that was previously selected for all-at-once IN constraint 10414 ** processing using the [sqlite3_vtab_in()] interface in the 10415 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 10416 ** an xFilter argument that was selected for all-at-once IN constraint 10417 ** processing, then these routines return [SQLITE_ERROR].)^ 10418 ** 10419 ** ^(Use these routines to access all values on the right-hand side 10420 ** of the IN constraint using code like the following: 10421 ** 10422 ** <blockquote><pre> 10423 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 10424 ** rc==SQLITE_OK && pVal; 10425 ** rc=sqlite3_vtab_in_next(pList, &pVal) 10426 ** ){ 10427 ** // do something with pVal 10428 ** } 10429 ** if( rc!=SQLITE_DONE ){ 10430 ** // an error has occurred 10431 ** } 10432 ** </pre></blockquote>)^ 10433 ** 10434 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 10435 ** routines return SQLITE_OK and set *P to point to the first or next value 10436 ** on the RHS of the IN constraint. ^If there are no more values on the 10437 ** right hand side of the IN constraint, then *P is set to NULL and these 10438 ** routines return [SQLITE_DONE]. ^The return value might be 10439 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 10440 ** 10441 ** The *ppOut values returned by these routines are only valid until the 10442 ** next call to either of these routines or until the end of the xFilter 10443 ** method from which these routines were called. If the virtual table 10444 ** implementation needs to retain the *ppOut values for longer, it must make 10445 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 10446 */ 10447 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 10448 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 10449 10450 /* 10451 ** CAPI3REF: Constraint values in xBestIndex() 10452 ** METHOD: sqlite3_index_info 10453 ** 10454 ** This API may only be used from within the [xBestIndex|xBestIndex method] 10455 ** of a [virtual table] implementation. The result of calling this interface 10456 ** from outside of an xBestIndex method are undefined and probably harmful. 10457 ** 10458 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 10459 ** the [xBestIndex] method of a [virtual table] implementation, with P being 10460 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 10461 ** J being a 0-based index into P->aConstraint[], then this routine 10462 ** attempts to set *V to the value of the right-hand operand of 10463 ** that constraint if the right-hand operand is known. ^If the 10464 ** right-hand operand is not known, then *V is set to a NULL pointer. 10465 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 10466 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 10467 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 10468 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 10469 ** can return a result code other than SQLITE_OK or SQLITE_NOTFOUND if 10470 ** something goes wrong. 10471 ** 10472 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 10473 ** the right-hand operand of a constraint is a literal value in the original 10474 ** SQL statement. If the right-hand operand is an expression or a reference 10475 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 10476 ** will probably return [SQLITE_NOTFOUND]. 10477 ** 10478 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 10479 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 10480 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 10481 ** 10482 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 10483 ** and remains valid for the duration of the xBestIndex method call. 10484 ** ^When xBestIndex returns, the sqlite3_value object returned by 10485 ** sqlite3_vtab_rhs_value() is automatically deallocated. 10486 ** 10487 ** The "_rhs_" in the name of this routine is an abbreviation for 10488 ** "Right-Hand Side". 10489 */ 10490 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 10491 10492 /* 10493 ** CAPI3REF: Conflict resolution modes 10494 ** KEYWORDS: {conflict resolution mode} 10495 ** 10496 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 10497 ** inform a [virtual table] implementation of the [ON CONFLICT] mode 10498 ** for the SQL statement being evaluated. 10499 ** 10500 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 10501 ** return value from the [sqlite3_set_authorizer()] callback and that 10502 ** [SQLITE_ABORT] is also a [result code]. 10503 */ 10504 #define SQLITE_ROLLBACK 1 10505 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 10506 #define SQLITE_FAIL 3 10507 /* #define SQLITE_ABORT 4 // Also an error code */ 10508 #define SQLITE_REPLACE 5 10509 10510 /* 10511 ** CAPI3REF: Prepared Statement Scan Status Opcodes 10512 ** KEYWORDS: {scanstatus options} 10513 ** 10514 ** The following constants can be used for the T parameter to the 10515 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 10516 ** different metric for sqlite3_stmt_scanstatus() to return. 10517 ** 10518 ** When the value returned to V is a string, space to hold that string is 10519 ** managed by the prepared statement S and will be automatically freed when 10520 ** S is finalized. 10521 ** 10522 ** Not all values are available for all query elements. When a value is 10523 ** not available, the output variable is set to -1 if the value is numeric, 10524 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME). 10525 ** 10526 ** <dl> 10527 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 10528 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 10529 ** set to the total number of times that the X-th loop has run.</dd> 10530 ** 10531 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 10532 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 10533 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 10534 ** 10535 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 10536 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 10537 ** query planner's estimate for the average number of rows output from each 10538 ** iteration of the X-th loop. If the query planner's estimate was accurate, 10539 ** then this value will approximate the quotient NVISIT/NLOOP and the 10540 ** product of this value for all prior loops with the same SELECTID will 10541 ** be the NLOOP value for the current loop.</dd> 10542 ** 10543 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 10544 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10545 ** to a zero-terminated UTF-8 string containing the name of the index or table 10546 ** used for the X-th loop.</dd> 10547 ** 10548 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 10549 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10550 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 10551 ** description for the X-th loop.</dd> 10552 ** 10553 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt> 10554 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 10555 ** id for the X-th query plan element. The id value is unique within the 10556 ** statement. The select-id is the same value as is output in the first 10557 ** column of an [EXPLAIN QUERY PLAN] query.</dd> 10558 ** 10559 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt> 10560 ** <dd>The "int" variable pointed to by the V parameter will be set to the 10561 ** id of the parent of the current query element, if applicable, or 10562 ** to zero if the query element has no parent. This is the same value as 10563 ** returned in the second column of an [EXPLAIN QUERY PLAN] query.</dd> 10564 ** 10565 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt> 10566 ** <dd>The sqlite3_int64 output value is set to the number of cycles, 10567 ** according to the processor time-stamp counter, that elapsed while the 10568 ** query element was being processed. This value is not available for 10569 ** all query elements - if it is unavailable the output variable is 10570 ** set to -1.</dd> 10571 ** </dl> 10572 */ 10573 #define SQLITE_SCANSTAT_NLOOP 0 10574 #define SQLITE_SCANSTAT_NVISIT 1 10575 #define SQLITE_SCANSTAT_EST 2 10576 #define SQLITE_SCANSTAT_NAME 3 10577 #define SQLITE_SCANSTAT_EXPLAIN 4 10578 #define SQLITE_SCANSTAT_SELECTID 5 10579 #define SQLITE_SCANSTAT_PARENTID 6 10580 #define SQLITE_SCANSTAT_NCYCLE 7 10581 10582 /* 10583 ** CAPI3REF: Prepared Statement Scan Status 10584 ** METHOD: sqlite3_stmt 10585 ** 10586 ** These interfaces return information about the predicted and measured 10587 ** performance for pStmt. Advanced applications can use this 10588 ** interface to compare the predicted and the measured performance and 10589 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 10590 ** 10591 ** Since this interface is expected to be rarely used, it is only 10592 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 10593 ** compile-time option. 10594 ** 10595 ** The "iScanStatusOp" parameter determines which status information to return. 10596 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 10597 ** of this interface is undefined. ^The requested measurement is written into 10598 ** a variable pointed to by the "pOut" parameter. 10599 ** 10600 ** The "flags" parameter must be passed a mask of flags. At present only 10601 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX 10602 ** is specified, then status information is available for all elements 10603 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If 10604 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements 10605 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of 10606 ** the EXPLAIN QUERY PLAN output) are available. Invoking API 10607 ** sqlite3_stmt_scanstatus() is equivalent to calling 10608 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter. 10609 ** 10610 ** Parameter "idx" identifies the specific query element to retrieve statistics 10611 ** for. Query elements are numbered starting from zero. A value of -1 may 10612 ** retrieve statistics for the entire query. ^If idx is out of range 10613 ** - less than -1 or greater than or equal to the total number of query 10614 ** elements used to implement the statement - a non-zero value is returned and 10615 ** the variable that pOut points to is unchanged. 10616 ** 10617 ** See also: [sqlite3_stmt_scanstatus_reset()] 10618 */ 10619 SQLITE_API int sqlite3_stmt_scanstatus( 10620 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10621 int idx, /* Index of loop to report on */ 10622 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10623 void *pOut /* Result written here */ 10624 ); 10625 SQLITE_API int sqlite3_stmt_scanstatus_v2( 10626 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10627 int idx, /* Index of loop to report on */ 10628 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10629 int flags, /* Mask of flags defined below */ 10630 void *pOut /* Result written here */ 10631 ); 10632 10633 /* 10634 ** CAPI3REF: Prepared Statement Scan Status 10635 ** KEYWORDS: {scan status flags} 10636 */ 10637 #define SQLITE_SCANSTAT_COMPLEX 0x0001 10638 10639 /* 10640 ** CAPI3REF: Zero Scan-Status Counters 10641 ** METHOD: sqlite3_stmt 10642 ** 10643 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 10644 ** 10645 ** This API is only available if the library is built with pre-processor 10646 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 10647 */ 10648 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 10649 10650 /* 10651 ** CAPI3REF: Flush caches to disk mid-transaction 10652 ** METHOD: sqlite3 10653 ** 10654 ** ^If a write-transaction is open on [database connection] D when the 10655 ** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty 10656 ** pages in the pager-cache that are not currently in use are written out 10657 ** to disk. A dirty page may be in use if a database cursor created by an 10658 ** active SQL statement is reading from it, or if it is page 1 of a database 10659 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 10660 ** interface flushes caches for all schemas - "main", "temp", and 10661 ** any [attached] databases. 10662 ** 10663 ** ^If this function needs to obtain extra database locks before dirty pages 10664 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 10665 ** immediately and there is a busy-handler callback configured, it is invoked 10666 ** in the usual manner. ^If the required lock still cannot be obtained, then 10667 ** the database is skipped and an attempt made to flush any dirty pages 10668 ** belonging to the next (if any) database. ^If any databases are skipped 10669 ** because locks cannot be obtained, but no other error occurs, this 10670 ** function returns SQLITE_BUSY. 10671 ** 10672 ** ^If any other error occurs while flushing dirty pages to disk (for 10673 ** example an IO error or out-of-memory condition), then processing is 10674 ** abandoned and an SQLite [error code] is returned to the caller immediately. 10675 ** 10676 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10677 ** 10678 ** ^This function does not set the database handle error code or message 10679 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10680 */ 10681 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10682 10683 /* 10684 ** CAPI3REF: The pre-update hook. 10685 ** METHOD: sqlite3 10686 ** 10687 ** ^These interfaces are only available if SQLite is compiled using the 10688 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10689 ** 10690 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10691 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10692 ** on a database table. 10693 ** ^At most one preupdate hook may be registered at a time on a single 10694 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10695 ** the previous setting. 10696 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10697 ** with a NULL pointer as the second parameter. 10698 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10699 ** the first parameter to callbacks. 10700 ** 10701 ** ^The preupdate hook only fires for changes to real database tables; the 10702 ** preupdate hook is not invoked for changes to [virtual tables] or to 10703 ** system tables like sqlite_sequence or sqlite_stat1. 10704 ** 10705 ** ^The second parameter to the preupdate callback is a pointer to 10706 ** the [database connection] that registered the preupdate hook. 10707 ** ^The third parameter to the preupdate callback is one of the constants 10708 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10709 ** kind of update operation that is about to occur. 10710 ** ^(The fourth parameter to the preupdate callback is the name of the 10711 ** database within the database connection that is being modified. This 10712 ** will be "main" for the main database or "temp" for TEMP tables or 10713 ** the name given after the AS keyword in the [ATTACH] statement for attached 10714 ** databases.)^ 10715 ** ^The fifth parameter to the preupdate callback is the name of the 10716 ** table that is being modified. 10717 ** 10718 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 10719 ** parameter passed to the preupdate callback is the initial [rowid] of the 10720 ** row being modified or deleted. For an INSERT operation on a rowid table, 10721 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10722 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10723 ** seventh parameter is the final rowid value of the row being inserted 10724 ** or updated. The value of the seventh parameter passed to the callback 10725 ** function is not defined for operations on WITHOUT ROWID tables, or for 10726 ** DELETE operations on rowid tables. 10727 ** 10728 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from 10729 ** the previous call on the same [database connection] D, or NULL for 10730 ** the first call on D. 10731 ** 10732 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10733 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10734 ** provide additional information about a preupdate event. These routines 10735 ** may only be called from within a preupdate callback. Invoking any of 10736 ** these routines from outside of a preupdate callback or with a 10737 ** [database connection] pointer that is different from the one supplied 10738 ** to the preupdate callback results in undefined and probably undesirable 10739 ** behavior. 10740 ** 10741 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10742 ** in the row that is being inserted, updated, or deleted. 10743 ** 10744 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10745 ** a [protected sqlite3_value] that contains the value of the Nth column of 10746 ** the table row before it is updated. The N parameter must be between 0 10747 ** and one less than the number of columns or the behavior will be 10748 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10749 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10750 ** behavior is undefined. The [sqlite3_value] that P points to 10751 ** will be destroyed when the preupdate callback returns. 10752 ** 10753 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10754 ** a [protected sqlite3_value] that contains the value of the Nth column of 10755 ** the table row after it is updated. The N parameter must be between 0 10756 ** and one less than the number of columns or the behavior will be 10757 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10758 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10759 ** behavior is undefined. The [sqlite3_value] that P points to 10760 ** will be destroyed when the preupdate callback returns. 10761 ** 10762 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10763 ** callback was invoked as a result of a direct insert, update, or delete 10764 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10765 ** triggers; or 2 for changes resulting from triggers called by top-level 10766 ** triggers; and so forth. 10767 ** 10768 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10769 ** the pre-update hook is invoked with SQLITE_DELETE, because 10770 ** the new values are not yet available. In this case, when a 10771 ** callback made with op==SQLITE_DELETE is actually a write using the 10772 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10773 ** the index of the column being written. In other cases, where the 10774 ** pre-update hook is being invoked for some other reason, including a 10775 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10776 ** 10777 ** See also: [sqlite3_update_hook()] 10778 */ 10779 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10780 SQLITE_API void *sqlite3_preupdate_hook( 10781 sqlite3 *db, 10782 void(*xPreUpdate)( 10783 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10784 sqlite3 *db, /* Database handle */ 10785 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10786 char const *zDb, /* Database name */ 10787 char const *zName, /* Table name */ 10788 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10789 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10790 ), 10791 void* 10792 ); 10793 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10794 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10795 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10796 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10797 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10798 #endif 10799 10800 /* 10801 ** CAPI3REF: Low-level system error code 10802 ** METHOD: sqlite3 10803 ** 10804 ** ^Attempt to return the underlying operating system error code or error 10805 ** number that caused the most recent I/O error or failure to open a file. 10806 ** The return value is OS-dependent. For example, on unix systems, after 10807 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10808 ** called to get back the underlying "errno" that caused the problem, such 10809 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10810 */ 10811 SQLITE_API int sqlite3_system_errno(sqlite3*); 10812 10813 /* 10814 ** CAPI3REF: Database Snapshot 10815 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10816 ** 10817 ** An instance of the snapshot object records the state of a [WAL mode] 10818 ** database for some specific point in history. 10819 ** 10820 ** In [WAL mode], multiple [database connections] that are open on the 10821 ** same database file can each be reading a different historical version 10822 ** of the database file. When a [database connection] begins a read 10823 ** transaction, that connection sees an unchanging copy of the database 10824 ** as it existed for the point in time when the transaction first started. 10825 ** Subsequent changes to the database from other connections are not seen 10826 ** by the reader until a new read transaction is started. 10827 ** 10828 ** The sqlite3_snapshot object records state information about an historical 10829 ** version of the database file so that it is possible to later open a new read 10830 ** transaction that sees that historical version of the database rather than 10831 ** the most recent version. 10832 */ 10833 typedef struct sqlite3_snapshot { 10834 unsigned char hidden[48]; 10835 } sqlite3_snapshot; 10836 10837 /* 10838 ** CAPI3REF: Record A Database Snapshot 10839 ** CONSTRUCTOR: sqlite3_snapshot 10840 ** 10841 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10842 ** new [sqlite3_snapshot] object that records the current state of 10843 ** schema S in database connection D. ^On success, the 10844 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10845 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10846 ** If there is not already a read-transaction open on schema S when 10847 ** this function is called, one is opened automatically. 10848 ** 10849 ** If a read-transaction is opened by this function, then it is guaranteed 10850 ** that the returned snapshot object may not be invalidated by a database 10851 ** writer or checkpointer until after the read-transaction is closed. This 10852 ** is not guaranteed if a read-transaction is already open when this 10853 ** function is called. In that case, any subsequent write or checkpoint 10854 ** operation on the database may invalidate the returned snapshot handle, 10855 ** even while the read-transaction remains open. 10856 ** 10857 ** The following must be true for this function to succeed. If any of 10858 ** the following statements are false when sqlite3_snapshot_get() is 10859 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10860 ** in this case. 10861 ** 10862 ** <ul> 10863 ** <li> The database handle must not be in [autocommit mode]. 10864 ** 10865 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10866 ** 10867 ** <li> There must not be a write transaction open on schema S of database 10868 ** connection D. 10869 ** 10870 ** <li> One or more transactions must have been written to the current wal 10871 ** file since it was created on disk (by any connection). This means 10872 ** that a snapshot cannot be taken on a wal mode database with no wal 10873 ** file immediately after it is first opened. At least one transaction 10874 ** must be written to it first. 10875 ** </ul> 10876 ** 10877 ** This function may also return SQLITE_NOMEM. If it is called with the 10878 ** database handle in autocommit mode but fails for some other reason, 10879 ** whether or not a read transaction is opened on schema S is undefined. 10880 ** 10881 ** The [sqlite3_snapshot] object returned from a successful call to 10882 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10883 ** to avoid a memory leak. 10884 ** 10885 ** The [sqlite3_snapshot_get()] interface is only available when the 10886 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10887 */ 10888 SQLITE_API int sqlite3_snapshot_get( 10889 sqlite3 *db, 10890 const char *zSchema, 10891 sqlite3_snapshot **ppSnapshot 10892 ); 10893 10894 /* 10895 ** CAPI3REF: Start a read transaction on an historical snapshot 10896 ** METHOD: sqlite3_snapshot 10897 ** 10898 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10899 ** transaction or upgrades an existing one for schema S of 10900 ** [database connection] D such that the read transaction refers to 10901 ** historical [snapshot] P, rather than the most recent change to the 10902 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10903 ** on success or an appropriate [error code] if it fails. 10904 ** 10905 ** ^In order to succeed, the database connection must not be in 10906 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10907 ** is already a read transaction open on schema S, then the database handle 10908 ** must have no active statements (SELECT statements that have been passed 10909 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10910 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10911 ** if schema S does not exist, or if the snapshot object is invalid. 10912 ** 10913 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10914 ** snapshot has been overwritten by a [checkpoint]. In this case 10915 ** SQLITE_ERROR_SNAPSHOT is returned. 10916 ** 10917 ** If there is already a read transaction open when this function is 10918 ** invoked, then the same read transaction remains open (on the same 10919 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10920 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10921 ** SQLITE_IOERR error code - is returned, then the final state of the 10922 ** read transaction is undefined. If SQLITE_OK is returned, then the 10923 ** read transaction is now open on database snapshot P. 10924 ** 10925 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10926 ** database connection D does not know that the database file for 10927 ** schema S is in [WAL mode]. A database connection might not know 10928 ** that the database file is in [WAL mode] if there has been no prior 10929 ** I/O on that database connection, or if the database entered [WAL mode] 10930 ** after the most recent I/O on the database connection.)^ 10931 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10932 ** database connection in order to make it ready to use snapshots.) 10933 ** 10934 ** The [sqlite3_snapshot_open()] interface is only available when the 10935 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10936 */ 10937 SQLITE_API int sqlite3_snapshot_open( 10938 sqlite3 *db, 10939 const char *zSchema, 10940 sqlite3_snapshot *pSnapshot 10941 ); 10942 10943 /* 10944 ** CAPI3REF: Destroy a snapshot 10945 ** DESTRUCTOR: sqlite3_snapshot 10946 ** 10947 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10948 ** The application must eventually free every [sqlite3_snapshot] object 10949 ** using this routine to avoid a memory leak. 10950 ** 10951 ** The [sqlite3_snapshot_free()] interface is only available when the 10952 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10953 */ 10954 SQLITE_API void sqlite3_snapshot_free(sqlite3_snapshot*); 10955 10956 /* 10957 ** CAPI3REF: Compare the ages of two snapshot handles. 10958 ** METHOD: sqlite3_snapshot 10959 ** 10960 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10961 ** of two valid snapshot handles. 10962 ** 10963 ** If the two snapshot handles are not associated with the same database 10964 ** file, the result of the comparison is undefined. 10965 ** 10966 ** Additionally, the result of the comparison is only valid if both of the 10967 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10968 ** last time the wal file was deleted. The wal file is deleted when the 10969 ** database is changed back to rollback mode or when the number of database 10970 ** clients drops to zero. If either snapshot handle was obtained before the 10971 ** wal file was last deleted, the value returned by this function 10972 ** is undefined. 10973 ** 10974 ** Otherwise, this API returns a negative value if P1 refers to an older 10975 ** snapshot than P2, zero if the two handles refer to the same database 10976 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10977 ** 10978 ** This interface is only available if SQLite is compiled with the 10979 ** [SQLITE_ENABLE_SNAPSHOT] option. 10980 */ 10981 SQLITE_API int sqlite3_snapshot_cmp( 10982 sqlite3_snapshot *p1, 10983 sqlite3_snapshot *p2 10984 ); 10985 10986 /* 10987 ** CAPI3REF: Recover snapshots from a wal file 10988 ** METHOD: sqlite3_snapshot 10989 ** 10990 ** If a [WAL file] remains on disk after all database connections close 10991 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10992 ** or because the last process to have the database opened exited without 10993 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10994 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10995 ** will only be able to open the last transaction added to the WAL file 10996 ** even though the WAL file contains other valid transactions. 10997 ** 10998 ** This function attempts to scan the WAL file associated with database zDb 10999 ** of database handle db and make all valid snapshots available to 11000 ** sqlite3_snapshot_open(). It is an error if there is already a read 11001 ** transaction open on the database, or if the database is not a WAL mode 11002 ** database. 11003 ** 11004 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 11005 ** 11006 ** This interface is only available if SQLite is compiled with the 11007 ** [SQLITE_ENABLE_SNAPSHOT] option. 11008 */ 11009 SQLITE_API int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 11010 11011 /* 11012 ** CAPI3REF: Serialize a database 11013 ** 11014 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to 11015 ** memory that is a serialization of the S database on 11016 ** [database connection] D. If S is a NULL pointer, the main database is used. 11017 ** If P is not a NULL pointer, then the size of the database in bytes 11018 ** is written into *P. 11019 ** 11020 ** For an ordinary on-disk database file, the serialization is just a 11021 ** copy of the disk file. For an in-memory database or a "TEMP" database, 11022 ** the serialization is the same sequence of bytes which would be written 11023 ** to disk if that database were backed up to disk. 11024 ** 11025 ** The usual case is that sqlite3_serialize() copies the serialization of 11026 ** the database into memory obtained from [sqlite3_malloc64()] and returns 11027 ** a pointer to that memory. The caller is responsible for freeing the 11028 ** returned value to avoid a memory leak. However, if the F argument 11029 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 11030 ** are made, and the sqlite3_serialize() function will return a pointer 11031 ** to the contiguous memory representation of the database that SQLite 11032 ** is currently using for that database, or NULL if no such contiguous 11033 ** memory representation of the database exists. A contiguous memory 11034 ** representation of the database will usually only exist if there has 11035 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 11036 ** values of D and S. 11037 ** The size of the database is written into *P even if the 11038 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 11039 ** of the database exists. 11040 ** 11041 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set, 11042 ** the returned buffer content will remain accessible and unchanged 11043 ** until either the next write operation on the connection or when 11044 ** the connection is closed, and applications must not modify the 11045 ** buffer. If the bit had been clear, the returned buffer will not 11046 ** be accessed by SQLite after the call. 11047 ** 11048 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 11049 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 11050 ** allocation error occurs. 11051 ** 11052 ** This interface is omitted if SQLite is compiled with the 11053 ** [SQLITE_OMIT_DESERIALIZE] option. 11054 */ 11055 SQLITE_API unsigned char *sqlite3_serialize( 11056 sqlite3 *db, /* The database connection */ 11057 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 11058 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 11059 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 11060 ); 11061 11062 /* 11063 ** CAPI3REF: Flags for sqlite3_serialize 11064 ** 11065 ** Zero or more of the following constants can be OR-ed together for 11066 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 11067 ** 11068 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 11069 ** a pointer to contiguous in-memory database that it is currently using, 11070 ** without making a copy of the database. If SQLite is not currently using 11071 ** a contiguous in-memory database, then this option causes 11072 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 11073 ** using a contiguous in-memory database if it has been initialized by a 11074 ** prior call to [sqlite3_deserialize()]. 11075 */ 11076 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 11077 11078 /* 11079 ** CAPI3REF: Deserialize a database 11080 ** 11081 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 11082 ** [database connection] D to disconnect from database S and then 11083 ** reopen S as an in-memory database based on the serialization 11084 ** contained in P. If S is a NULL pointer, the main database is 11085 ** used. The serialized database P is N bytes in size. M is the size 11086 ** of the buffer P, which might be larger than N. If M is larger than 11087 ** N, and the SQLITE_DESERIALIZE_READONLY bit is not set in F, then 11088 ** SQLite is permitted to add content to the in-memory database as 11089 ** long as the total size does not exceed M bytes. 11090 ** 11091 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 11092 ** invoke sqlite3_free() on the serialization buffer when the database 11093 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 11094 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 11095 ** if writes on the database cause it to grow larger than M bytes. 11096 ** 11097 ** Applications must not modify the buffer P or invalidate it before 11098 ** the database connection D is closed. 11099 ** 11100 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 11101 ** database is currently in a read transaction or is involved in a backup 11102 ** operation. 11103 ** 11104 ** It is not possible to deserialize into the TEMP database. If the 11105 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 11106 ** function returns SQLITE_ERROR. 11107 ** 11108 ** The deserialized database should not be in [WAL mode]. If the database 11109 ** is in WAL mode, then any attempt to use the database file will result 11110 ** in an [SQLITE_CANTOPEN] error. The application can set the 11111 ** [file format version numbers] (bytes 18 and 19) of the input database P 11112 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the 11113 ** database file into rollback mode and work around this limitation. 11114 ** 11115 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 11116 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 11117 ** [sqlite3_free()] is invoked on argument P prior to returning. 11118 ** 11119 ** This interface is omitted if SQLite is compiled with the 11120 ** [SQLITE_OMIT_DESERIALIZE] option. 11121 */ 11122 SQLITE_API int sqlite3_deserialize( 11123 sqlite3 *db, /* The database connection */ 11124 const char *zSchema, /* Which DB to reopen with the deserialization */ 11125 unsigned char *pData, /* The serialized database content */ 11126 sqlite3_int64 szDb, /* Number of bytes in the deserialization */ 11127 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 11128 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 11129 ); 11130 11131 /* 11132 ** CAPI3REF: Flags for sqlite3_deserialize() 11133 ** 11134 ** The following are allowed values for the 6th argument (the F argument) to 11135 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 11136 ** 11137 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 11138 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 11139 ** and that SQLite should take ownership of this memory and automatically 11140 ** free it when it has finished using it. Without this flag, the caller 11141 ** is responsible for freeing any dynamically allocated memory. 11142 ** 11143 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 11144 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 11145 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 11146 ** Without this flag, the deserialized database cannot increase in size beyond 11147 ** the number of bytes specified by the M parameter. 11148 ** 11149 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 11150 ** should be treated as read-only. 11151 */ 11152 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 11153 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 11154 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 11155 11156 /* 11157 ** CAPI3REF: Bind array values to the CARRAY table-valued function 11158 ** 11159 ** The sqlite3_carray_bind(S,I,P,N,F,X) interface binds an array value to 11160 ** one of the first argument of the [carray() table-valued function]. The 11161 ** S parameter is a pointer to the [prepared statement] that uses the carray() 11162 ** functions. I is the parameter index to be bound. P is a pointer to the 11163 ** array to be bound, and N is the number of eements in the array. The 11164 ** F argument is one of constants [SQLITE_CARRAY_INT32], [SQLITE_CARRAY_INT64], 11165 ** [SQLITE_CARRAY_DOUBLE], [SQLITE_CARRAY_TEXT], or [SQLITE_CARRAY_BLOB] to 11166 ** indicate the datatype of the array being bound. The X argument is not a 11167 ** NULL pointer, then SQLite will invoke the function X on the P parameter 11168 ** after it has finished using P, even if the call to 11169 ** sqlite3_carray_bind() fails. The special-case finalizer 11170 ** SQLITE_TRANSIENT has no effect here. 11171 */ 11172 SQLITE_API int sqlite3_carray_bind( 11173 sqlite3_stmt *pStmt, /* Statement to be bound */ 11174 int i, /* Parameter index */ 11175 void *aData, /* Pointer to array data */ 11176 int nData, /* Number of data elements */ 11177 int mFlags, /* CARRAY flags */ 11178 void (*xDel)(void*) /* Destructor for aData */ 11179 ); 11180 11181 /* 11182 ** CAPI3REF: Datatypes for the CARRAY table-valued function 11183 ** 11184 ** The fifth argument to the [sqlite3_carray_bind()] interface musts be 11185 ** one of the following constants, to specify the datatype of the array 11186 ** that is being bound into the [carray table-valued function]. 11187 */ 11188 #define SQLITE_CARRAY_INT32 0 /* Data is 32-bit signed integers */ 11189 #define SQLITE_CARRAY_INT64 1 /* Data is 64-bit signed integers */ 11190 #define SQLITE_CARRAY_DOUBLE 2 /* Data is doubles */ 11191 #define SQLITE_CARRAY_TEXT 3 /* Data is char* */ 11192 #define SQLITE_CARRAY_BLOB 4 /* Data is struct iovec */ 11193 11194 /* 11195 ** Versions of the above #defines that omit the initial SQLITE_, for 11196 ** legacy compatibility. 11197 */ 11198 #define CARRAY_INT32 0 /* Data is 32-bit signed integers */ 11199 #define CARRAY_INT64 1 /* Data is 64-bit signed integers */ 11200 #define CARRAY_DOUBLE 2 /* Data is doubles */ 11201 #define CARRAY_TEXT 3 /* Data is char* */ 11202 #define CARRAY_BLOB 4 /* Data is struct iovec */ 11203 11204 /* 11205 ** Undo the hack that converts floating point types to integer for 11206 ** builds on processors without floating point support. 11207 */ 11208 #ifdef SQLITE_OMIT_FLOATING_POINT 11209 # undef double 11210 #endif 11211 11212 #if defined(__wasi__) 11213 # undef SQLITE_WASI 11214 # define SQLITE_WASI 1 11215 # ifndef SQLITE_OMIT_LOAD_EXTENSION 11216 # define SQLITE_OMIT_LOAD_EXTENSION 11217 # endif 11218 # ifndef SQLITE_THREADSAFE 11219 # define SQLITE_THREADSAFE 0 11220 # endif 11221 #endif 11222 11223 #ifdef __cplusplus 11224 } /* End of the 'extern "C"' block */ 11225 #endif 11226 /* #endif for SQLITE3_H will be added by mksqlite3.tcl */ 11227 11228 /******** Begin file sqlite3rtree.h *********/ 11229 /* 11230 ** 2010 August 30 11231 ** 11232 ** The author disclaims copyright to this source code. In place of 11233 ** a legal notice, here is a blessing: 11234 ** 11235 ** May you do good and not evil. 11236 ** May you find forgiveness for yourself and forgive others. 11237 ** May you share freely, never taking more than you give. 11238 ** 11239 ************************************************************************* 11240 */ 11241 11242 #ifndef _SQLITE3RTREE_H_ 11243 #define _SQLITE3RTREE_H_ 11244 11245 11246 #ifdef __cplusplus 11247 extern "C" { 11248 #endif 11249 11250 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 11251 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 11252 11253 /* The double-precision datatype used by RTree depends on the 11254 ** SQLITE_RTREE_INT_ONLY compile-time option. 11255 */ 11256 #ifdef SQLITE_RTREE_INT_ONLY 11257 typedef sqlite3_int64 sqlite3_rtree_dbl; 11258 #else 11259 typedef double sqlite3_rtree_dbl; 11260 #endif 11261 11262 /* 11263 ** Register a geometry callback named zGeom that can be used as part of an 11264 ** R-Tree geometry query as follows: 11265 ** 11266 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 11267 */ 11268 SQLITE_API int sqlite3_rtree_geometry_callback( 11269 sqlite3 *db, 11270 const char *zGeom, 11271 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 11272 void *pContext 11273 ); 11274 11275 11276 /* 11277 ** A pointer to a structure of the following type is passed as the first 11278 ** argument to callbacks registered using rtree_geometry_callback(). 11279 */ 11280 struct sqlite3_rtree_geometry { 11281 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 11282 int nParam; /* Size of array aParam[] */ 11283 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 11284 void *pUser; /* Callback implementation user data */ 11285 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 11286 }; 11287 11288 /* 11289 ** Register a 2nd-generation geometry callback named zScore that can be 11290 ** used as part of an R-Tree geometry query as follows: 11291 ** 11292 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 11293 */ 11294 SQLITE_API int sqlite3_rtree_query_callback( 11295 sqlite3 *db, 11296 const char *zQueryFunc, 11297 int (*xQueryFunc)(sqlite3_rtree_query_info*), 11298 void *pContext, 11299 void (*xDestructor)(void*) 11300 ); 11301 11302 11303 /* 11304 ** A pointer to a structure of the following type is passed as the 11305 ** argument to scored geometry callback registered using 11306 ** sqlite3_rtree_query_callback(). 11307 ** 11308 ** Note that the first 5 fields of this structure are identical to 11309 ** sqlite3_rtree_geometry. This structure is a subclass of 11310 ** sqlite3_rtree_geometry. 11311 */ 11312 struct sqlite3_rtree_query_info { 11313 void *pContext; /* pContext from when function registered */ 11314 int nParam; /* Number of function parameters */ 11315 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 11316 void *pUser; /* callback can use this, if desired */ 11317 void (*xDelUser)(void*); /* function to free pUser */ 11318 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 11319 unsigned int *anQueue; /* Number of pending entries in the queue */ 11320 int nCoord; /* Number of coordinates */ 11321 int iLevel; /* Level of current node or entry */ 11322 int mxLevel; /* The largest iLevel value in the tree */ 11323 sqlite3_int64 iRowid; /* Rowid for current entry */ 11324 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 11325 int eParentWithin; /* Visibility of parent node */ 11326 int eWithin; /* OUT: Visibility */ 11327 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 11328 /* The following fields are only available in 3.8.11 and later */ 11329 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 11330 }; 11331 11332 /* 11333 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 11334 */ 11335 #define NOT_WITHIN 0 /* Object completely outside of query region */ 11336 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 11337 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 11338 11339 11340 #ifdef __cplusplus 11341 } /* end of the 'extern "C"' block */ 11342 #endif 11343 11344 #endif /* ifndef _SQLITE3RTREE_H_ */ 11345 11346 /******** End of sqlite3rtree.h *********/ 11347 /******** Begin file sqlite3session.h *********/ 11348 11349 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 11350 #define __SQLITESESSION_H_ 1 11351 11352 /* 11353 ** Make sure we can call this stuff from C++. 11354 */ 11355 #ifdef __cplusplus 11356 extern "C" { 11357 #endif 11358 11359 11360 /* 11361 ** CAPI3REF: Session Object Handle 11362 ** 11363 ** An instance of this object is a [session] that can be used to 11364 ** record changes to a database. 11365 */ 11366 typedef struct sqlite3_session sqlite3_session; 11367 11368 /* 11369 ** CAPI3REF: Changeset Iterator Handle 11370 ** 11371 ** An instance of this object acts as a cursor for iterating 11372 ** over the elements of a [changeset] or [patchset]. 11373 */ 11374 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 11375 11376 /* 11377 ** CAPI3REF: Create A New Session Object 11378 ** CONSTRUCTOR: sqlite3_session 11379 ** 11380 ** Create a new session object attached to database handle db. If successful, 11381 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 11382 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 11383 ** error code (e.g. SQLITE_NOMEM) is returned. 11384 ** 11385 ** It is possible to create multiple session objects attached to a single 11386 ** database handle. 11387 ** 11388 ** Session objects created using this function should be deleted using the 11389 ** [sqlite3session_delete()] function before the database handle that they 11390 ** are attached to is itself closed. If the database handle is closed before 11391 ** the session object is deleted, then the results of calling any session 11392 ** module function, including [sqlite3session_delete()] on the session object 11393 ** are undefined. 11394 ** 11395 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 11396 ** is not possible for an application to register a pre-update hook on a 11397 ** database handle that has one or more session objects attached. Nor is 11398 ** it possible to create a session object attached to a database handle for 11399 ** which a pre-update hook is already defined. The results of attempting 11400 ** either of these things are undefined. 11401 ** 11402 ** The session object will be used to create changesets for tables in 11403 ** database zDb, where zDb is either "main", or "temp", or the name of an 11404 ** attached database. It is not an error if database zDb is not attached 11405 ** to the database when the session object is created. 11406 */ 11407 SQLITE_API int sqlite3session_create( 11408 sqlite3 *db, /* Database handle */ 11409 const char *zDb, /* Name of db (e.g. "main") */ 11410 sqlite3_session **ppSession /* OUT: New session object */ 11411 ); 11412 11413 /* 11414 ** CAPI3REF: Delete A Session Object 11415 ** DESTRUCTOR: sqlite3_session 11416 ** 11417 ** Delete a session object previously allocated using 11418 ** [sqlite3session_create()]. Once a session object has been deleted, the 11419 ** results of attempting to use pSession with any other session module 11420 ** function are undefined. 11421 ** 11422 ** Session objects must be deleted before the database handle to which they 11423 ** are attached is closed. Refer to the documentation for 11424 ** [sqlite3session_create()] for details. 11425 */ 11426 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 11427 11428 /* 11429 ** CAPI3REF: Configure a Session Object 11430 ** METHOD: sqlite3_session 11431 ** 11432 ** This method is used to configure a session object after it has been 11433 ** created. At present the only valid values for the second parameter are 11434 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID]. 11435 ** 11436 */ 11437 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 11438 11439 /* 11440 ** CAPI3REF: Options for sqlite3session_object_config 11441 ** 11442 ** The following values may passed as the the 2nd parameter to 11443 ** sqlite3session_object_config(). 11444 ** 11445 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 11446 ** This option is used to set, clear or query the flag that enables 11447 ** the [sqlite3session_changeset_size()] API. Because it imposes some 11448 ** computational overhead, this API is disabled by default. Argument 11449 ** pArg must point to a value of type (int). If the value is initially 11450 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 11451 ** is greater than 0, then the same API is enabled. Or, if the initial 11452 ** value is less than zero, no change is made. In all cases the (int) 11453 ** variable is set to 1 if the sqlite3session_changeset_size() API is 11454 ** enabled following the current call, or 0 otherwise. 11455 ** 11456 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 11457 ** the first table has been attached to the session object. 11458 ** 11459 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd> 11460 ** This option is used to set, clear or query the flag that enables 11461 ** collection of data for tables with no explicit PRIMARY KEY. 11462 ** 11463 ** Normally, tables with no explicit PRIMARY KEY are simply ignored 11464 ** by the sessions module. However, if this flag is set, it behaves 11465 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted 11466 ** as their leftmost columns. 11467 ** 11468 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 11469 ** the first table has been attached to the session object. 11470 */ 11471 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 11472 #define SQLITE_SESSION_OBJCONFIG_ROWID 2 11473 11474 /* 11475 ** CAPI3REF: Enable Or Disable A Session Object 11476 ** METHOD: sqlite3_session 11477 ** 11478 ** Enable or disable the recording of changes by a session object. When 11479 ** enabled, a session object records changes made to the database. When 11480 ** disabled - it does not. A newly created session object is enabled. 11481 ** Refer to the documentation for [sqlite3session_changeset()] for further 11482 ** details regarding how enabling and disabling a session object affects 11483 ** the eventual changesets. 11484 ** 11485 ** Passing zero to this function disables the session. Passing a value 11486 ** greater than zero enables it. Passing a value less than zero is a 11487 ** no-op, and may be used to query the current state of the session. 11488 ** 11489 ** The return value indicates the final state of the session object: 0 if 11490 ** the session is disabled, or 1 if it is enabled. 11491 */ 11492 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 11493 11494 /* 11495 ** CAPI3REF: Set Or Clear the Indirect Change Flag 11496 ** METHOD: sqlite3_session 11497 ** 11498 ** Each change recorded by a session object is marked as either direct or 11499 ** indirect. A change is marked as indirect if either: 11500 ** 11501 ** <ul> 11502 ** <li> The session object "indirect" flag is set when the change is 11503 ** made, or 11504 ** <li> The change is made by an SQL trigger or foreign key action 11505 ** instead of directly as a result of a users SQL statement. 11506 ** </ul> 11507 ** 11508 ** If a single row is affected by more than one operation within a session, 11509 ** then the change is considered indirect if all operations meet the criteria 11510 ** for an indirect change above, or direct otherwise. 11511 ** 11512 ** This function is used to set, clear or query the session object indirect 11513 ** flag. If the second argument passed to this function is zero, then the 11514 ** indirect flag is cleared. If it is greater than zero, the indirect flag 11515 ** is set. Passing a value less than zero does not modify the current value 11516 ** of the indirect flag, and may be used to query the current state of the 11517 ** indirect flag for the specified session object. 11518 ** 11519 ** The return value indicates the final state of the indirect flag: 0 if 11520 ** it is clear, or 1 if it is set. 11521 */ 11522 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 11523 11524 /* 11525 ** CAPI3REF: Attach A Table To A Session Object 11526 ** METHOD: sqlite3_session 11527 ** 11528 ** If argument zTab is not NULL, then it is the name of a table to attach 11529 ** to the session object passed as the first argument. All subsequent changes 11530 ** made to the table while the session object is enabled will be recorded. See 11531 ** documentation for [sqlite3session_changeset()] for further details. 11532 ** 11533 ** Or, if argument zTab is NULL, then changes are recorded for all tables 11534 ** in the database. If additional tables are added to the database (by 11535 ** executing "CREATE TABLE" statements) after this call is made, changes for 11536 ** the new tables are also recorded. 11537 ** 11538 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 11539 ** defined as part of their CREATE TABLE statement. It does not matter if the 11540 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 11541 ** KEY may consist of a single column, or may be a composite key. 11542 ** 11543 ** It is not an error if the named table does not exist in the database. Nor 11544 ** is it an error if the named table does not have a PRIMARY KEY. However, 11545 ** no changes will be recorded in either of these scenarios. 11546 ** 11547 ** Changes are not recorded for individual rows that have NULL values stored 11548 ** in one or more of their PRIMARY KEY columns. 11549 ** 11550 ** SQLITE_OK is returned if the call completes without error. Or, if an error 11551 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 11552 ** 11553 ** <h3>Special sqlite_stat1 Handling</h3> 11554 ** 11555 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 11556 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 11557 ** <pre> 11558 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 11559 ** </pre> 11560 ** 11561 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 11562 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 11563 ** are recorded for rows for which (idx IS NULL) is true. However, for such 11564 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 11565 ** patchset instead of a NULL value. This allows such changesets to be 11566 ** manipulated by legacy implementations of sqlite3changeset_invert(), 11567 ** concat() and similar. 11568 ** 11569 ** The sqlite3changeset_apply() function automatically converts the 11570 ** zero-length blob back to a NULL value when updating the sqlite_stat1 11571 ** table. However, if the application calls sqlite3changeset_new(), 11572 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 11573 ** iterator directly (including on a changeset iterator passed to a 11574 ** conflict-handler callback) then the X'' value is returned. The application 11575 ** must translate X'' to NULL itself if required. 11576 ** 11577 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 11578 ** changes made to the sqlite_stat1 table. Legacy versions of the 11579 ** sqlite3changeset_apply() function silently ignore any modifications to the 11580 ** sqlite_stat1 table that are part of a changeset or patchset. 11581 */ 11582 SQLITE_API int sqlite3session_attach( 11583 sqlite3_session *pSession, /* Session object */ 11584 const char *zTab /* Table name */ 11585 ); 11586 11587 /* 11588 ** CAPI3REF: Set a table filter on a Session Object. 11589 ** METHOD: sqlite3_session 11590 ** 11591 ** The second argument (xFilter) is the "filter callback". For changes to rows 11592 ** in tables that are not attached to the Session object, the filter is called 11593 ** to determine whether changes to the table's rows should be tracked or not. 11594 ** If xFilter returns 0, changes are not tracked. Note that once a table is 11595 ** attached, xFilter will not be called again. 11596 */ 11597 SQLITE_API void sqlite3session_table_filter( 11598 sqlite3_session *pSession, /* Session object */ 11599 int(*xFilter)( 11600 void *pCtx, /* Copy of third arg to _filter_table() */ 11601 const char *zTab /* Table name */ 11602 ), 11603 void *pCtx /* First argument passed to xFilter */ 11604 ); 11605 11606 /* 11607 ** CAPI3REF: Generate A Changeset From A Session Object 11608 ** METHOD: sqlite3_session 11609 ** 11610 ** Obtain a changeset containing changes to the tables attached to the 11611 ** session object passed as the first argument. If successful, 11612 ** set *ppChangeset to point to a buffer containing the changeset 11613 ** and *pnChangeset to the size of the changeset in bytes before returning 11614 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 11615 ** zero and return an SQLite error code. 11616 ** 11617 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 11618 ** each representing a change to a single row of an attached table. An INSERT 11619 ** change contains the values of each field of a new database row. A DELETE 11620 ** contains the original values of each field of a deleted database row. An 11621 ** UPDATE change contains the original values of each field of an updated 11622 ** database row along with the updated values for each updated non-primary-key 11623 ** column. It is not possible for an UPDATE change to represent a change that 11624 ** modifies the values of primary key columns. If such a change is made, it 11625 ** is represented in a changeset as a DELETE followed by an INSERT. 11626 ** 11627 ** Changes are not recorded for rows that have NULL values stored in one or 11628 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 11629 ** no corresponding change is present in the changesets returned by this 11630 ** function. If an existing row with one or more NULL values stored in 11631 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 11632 ** only an INSERT is appears in the changeset. Similarly, if an existing row 11633 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 11634 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 11635 ** DELETE change only. 11636 ** 11637 ** The contents of a changeset may be traversed using an iterator created 11638 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 11639 ** a database with a compatible schema using the [sqlite3changeset_apply()] 11640 ** API. 11641 ** 11642 ** Within a changeset generated by this function, all changes related to a 11643 ** single table are grouped together. In other words, when iterating through 11644 ** a changeset or when applying a changeset to a database, all changes related 11645 ** to a single table are processed before moving on to the next table. Tables 11646 ** are sorted in the same order in which they were attached (or auto-attached) 11647 ** to the sqlite3_session object. The order in which the changes related to 11648 ** a single table are stored is undefined. 11649 ** 11650 ** Following a successful call to this function, it is the responsibility of 11651 ** the caller to eventually free the buffer that *ppChangeset points to using 11652 ** [sqlite3_free()]. 11653 ** 11654 ** <h3>Changeset Generation</h3> 11655 ** 11656 ** Once a table has been attached to a session object, the session object 11657 ** records the primary key values of all new rows inserted into the table. 11658 ** It also records the original primary key and other column values of any 11659 ** deleted or updated rows. For each unique primary key value, data is only 11660 ** recorded once - the first time a row with said primary key is inserted, 11661 ** updated or deleted in the lifetime of the session. 11662 ** 11663 ** There is one exception to the previous paragraph: when a row is inserted, 11664 ** updated or deleted, if one or more of its primary key columns contain a 11665 ** NULL value, no record of the change is made. 11666 ** 11667 ** The session object therefore accumulates two types of records - those 11668 ** that consist of primary key values only (created when the user inserts 11669 ** a new record) and those that consist of the primary key values and the 11670 ** original values of other table columns (created when the users deletes 11671 ** or updates a record). 11672 ** 11673 ** When this function is called, the requested changeset is created using 11674 ** both the accumulated records and the current contents of the database 11675 ** file. Specifically: 11676 ** 11677 ** <ul> 11678 ** <li> For each record generated by an insert, the database is queried 11679 ** for a row with a matching primary key. If one is found, an INSERT 11680 ** change is added to the changeset. If no such row is found, no change 11681 ** is added to the changeset. 11682 ** 11683 ** <li> For each record generated by an update or delete, the database is 11684 ** queried for a row with a matching primary key. If such a row is 11685 ** found and one or more of the non-primary key fields have been 11686 ** modified from their original values, an UPDATE change is added to 11687 ** the changeset. Or, if no such row is found in the table, a DELETE 11688 ** change is added to the changeset. If there is a row with a matching 11689 ** primary key in the database, but all fields contain their original 11690 ** values, no change is added to the changeset. 11691 ** </ul> 11692 ** 11693 ** This means, amongst other things, that if a row is inserted and then later 11694 ** deleted while a session object is active, neither the insert nor the delete 11695 ** will be present in the changeset. Or if a row is deleted and then later a 11696 ** row with the same primary key values inserted while a session object is 11697 ** active, the resulting changeset will contain an UPDATE change instead of 11698 ** a DELETE and an INSERT. 11699 ** 11700 ** When a session object is disabled (see the [sqlite3session_enable()] API), 11701 ** it does not accumulate records when rows are inserted, updated or deleted. 11702 ** This may appear to have some counter-intuitive effects if a single row 11703 ** is written to more than once during a session. For example, if a row 11704 ** is inserted while a session object is enabled, then later deleted while 11705 ** the same session object is disabled, no INSERT record will appear in the 11706 ** changeset, even though the delete took place while the session was disabled. 11707 ** Or, if one field of a row is updated while a session is enabled, and 11708 ** then another field of the same row is updated while the session is disabled, 11709 ** the resulting changeset will contain an UPDATE change that updates both 11710 ** fields. 11711 */ 11712 SQLITE_API int sqlite3session_changeset( 11713 sqlite3_session *pSession, /* Session object */ 11714 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 11715 void **ppChangeset /* OUT: Buffer containing changeset */ 11716 ); 11717 11718 /* 11719 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 11720 ** METHOD: sqlite3_session 11721 ** 11722 ** By default, this function always returns 0. For it to return 11723 ** a useful result, the sqlite3_session object must have been configured 11724 ** to enable this API using sqlite3session_object_config() with the 11725 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 11726 ** 11727 ** When enabled, this function returns an upper limit, in bytes, for the size 11728 ** of the changeset that might be produced if sqlite3session_changeset() were 11729 ** called. The final changeset size might be equal to or smaller than the 11730 ** size in bytes returned by this function. 11731 */ 11732 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 11733 11734 /* 11735 ** CAPI3REF: Load The Difference Between Tables Into A Session 11736 ** METHOD: sqlite3_session 11737 ** 11738 ** If it is not already attached to the session object passed as the first 11739 ** argument, this function attaches table zTbl in the same manner as the 11740 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 11741 ** does not have a primary key, this function is a no-op (but does not return 11742 ** an error). 11743 ** 11744 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 11745 ** attached to the same database handle as the session object that contains 11746 ** a table compatible with the table attached to the session by this function. 11747 ** A table is considered compatible if it: 11748 ** 11749 ** <ul> 11750 ** <li> Has the same name, 11751 ** <li> Has the same set of columns declared in the same order, and 11752 ** <li> Has the same PRIMARY KEY definition. 11753 ** </ul> 11754 ** 11755 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 11756 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 11757 ** but no changes are added to the session object. As with other session 11758 ** APIs, tables without PRIMARY KEYs are simply ignored. 11759 ** 11760 ** This function adds a set of changes to the session object that could be 11761 ** used to update the table in database zFrom (call this the "from-table") 11762 ** so that its content is the same as the table attached to the session 11763 ** object (call this the "to-table"). Specifically: 11764 ** 11765 ** <ul> 11766 ** <li> For each row (primary key) that exists in the to-table but not in 11767 ** the from-table, an INSERT record is added to the session object. 11768 ** 11769 ** <li> For each row (primary key) that exists in the to-table but not in 11770 ** the from-table, a DELETE record is added to the session object. 11771 ** 11772 ** <li> For each row (primary key) that exists in both tables, but features 11773 ** different non-PK values in each, an UPDATE record is added to the 11774 ** session. 11775 ** </ul> 11776 ** 11777 ** To clarify, if this function is called and then a changeset constructed 11778 ** using [sqlite3session_changeset()], then after applying that changeset to 11779 ** database zFrom the contents of the two compatible tables would be 11780 ** identical. 11781 ** 11782 ** Unless the call to this function is a no-op as described above, it is an 11783 ** error if database zFrom does not exist or does not contain the required 11784 ** compatible table. 11785 ** 11786 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11787 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11788 ** may be set to point to a buffer containing an English language error 11789 ** message. It is the responsibility of the caller to free this buffer using 11790 ** sqlite3_free(). 11791 */ 11792 SQLITE_API int sqlite3session_diff( 11793 sqlite3_session *pSession, 11794 const char *zFromDb, 11795 const char *zTbl, 11796 char **pzErrMsg 11797 ); 11798 11799 11800 /* 11801 ** CAPI3REF: Generate A Patchset From A Session Object 11802 ** METHOD: sqlite3_session 11803 ** 11804 ** The differences between a patchset and a changeset are that: 11805 ** 11806 ** <ul> 11807 ** <li> DELETE records consist of the primary key fields only. The 11808 ** original values of other fields are omitted. 11809 ** <li> The original values of any modified fields are omitted from 11810 ** UPDATE records. 11811 ** </ul> 11812 ** 11813 ** A patchset blob may be used with up to date versions of all 11814 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11815 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11816 ** attempting to use a patchset blob with old versions of the 11817 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11818 ** 11819 ** Because the non-primary key "old.*" fields are omitted, no 11820 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11821 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 11822 ** in the same way as for changesets. 11823 ** 11824 ** Changes within a patchset are ordered in the same way as for changesets 11825 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11826 ** a single table are grouped together, tables appear in the order in which 11827 ** they were attached to the session object). 11828 */ 11829 SQLITE_API int sqlite3session_patchset( 11830 sqlite3_session *pSession, /* Session object */ 11831 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11832 void **ppPatchset /* OUT: Buffer containing patchset */ 11833 ); 11834 11835 /* 11836 ** CAPI3REF: Test if a changeset has recorded any changes. 11837 ** 11838 ** Return non-zero if no changes to attached tables have been recorded by 11839 ** the session object passed as the first argument. Otherwise, if one or 11840 ** more changes have been recorded, return zero. 11841 ** 11842 ** Even if this function returns zero, it is possible that calling 11843 ** [sqlite3session_changeset()] on the session handle may still return a 11844 ** changeset that contains no changes. This can happen when a row in 11845 ** an attached table is modified and then later on the original values 11846 ** are restored. However, if this function returns non-zero, then it is 11847 ** guaranteed that a call to sqlite3session_changeset() will return a 11848 ** changeset containing zero changes. 11849 */ 11850 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11851 11852 /* 11853 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11854 ** 11855 ** This API returns the total amount of heap memory in bytes currently 11856 ** used by the session object passed as the only argument. 11857 */ 11858 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11859 11860 /* 11861 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11862 ** CONSTRUCTOR: sqlite3_changeset_iter 11863 ** 11864 ** Create an iterator used to iterate through the contents of a changeset. 11865 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11866 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11867 ** SQLite error code is returned. 11868 ** 11869 ** The following functions can be used to advance and query a changeset 11870 ** iterator created by this function: 11871 ** 11872 ** <ul> 11873 ** <li> [sqlite3changeset_next()] 11874 ** <li> [sqlite3changeset_op()] 11875 ** <li> [sqlite3changeset_new()] 11876 ** <li> [sqlite3changeset_old()] 11877 ** </ul> 11878 ** 11879 ** It is the responsibility of the caller to eventually destroy the iterator 11880 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11881 ** changeset (pChangeset) must remain valid until after the iterator is 11882 ** destroyed. 11883 ** 11884 ** Assuming the changeset blob was created by one of the 11885 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11886 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11887 ** that apply to a single table are grouped together. This means that when 11888 ** an application iterates through a changeset using an iterator created by 11889 ** this function, all changes that relate to a single table are visited 11890 ** consecutively. There is no chance that the iterator will visit a change 11891 ** the applies to table X, then one for table Y, and then later on visit 11892 ** another change for table X. 11893 ** 11894 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11895 ** may be modified by passing a combination of 11896 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11897 ** 11898 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11899 ** and therefore subject to change. 11900 */ 11901 SQLITE_API int sqlite3changeset_start( 11902 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11903 int nChangeset, /* Size of changeset blob in bytes */ 11904 void *pChangeset /* Pointer to blob containing changeset */ 11905 ); 11906 SQLITE_API int sqlite3changeset_start_v2( 11907 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11908 int nChangeset, /* Size of changeset blob in bytes */ 11909 void *pChangeset, /* Pointer to blob containing changeset */ 11910 int flags /* SESSION_CHANGESETSTART_* flags */ 11911 ); 11912 11913 /* 11914 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11915 ** 11916 ** The following flags may passed via the 4th parameter to 11917 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11918 ** 11919 ** <dt>SQLITE_CHANGESETSTART_INVERT <dd> 11920 ** Invert the changeset while iterating through it. This is equivalent to 11921 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11922 ** It is an error to specify this flag with a patchset. 11923 */ 11924 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11925 11926 11927 /* 11928 ** CAPI3REF: Advance A Changeset Iterator 11929 ** METHOD: sqlite3_changeset_iter 11930 ** 11931 ** This function may only be used with iterators created by the function 11932 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11933 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11934 ** is returned and the call has no effect. 11935 ** 11936 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11937 ** does not point to any change in the changeset. Assuming the changeset 11938 ** is not empty, the first call to this function advances the iterator to 11939 ** point to the first change in the changeset. Each subsequent call advances 11940 ** the iterator to point to the next change in the changeset (if any). If 11941 ** no error occurs and the iterator points to a valid change after a call 11942 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11943 ** Otherwise, if all changes in the changeset have already been visited, 11944 ** SQLITE_DONE is returned. 11945 ** 11946 ** If an error occurs, an SQLite error code is returned. Possible error 11947 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11948 ** SQLITE_NOMEM. 11949 */ 11950 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11951 11952 /* 11953 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11954 ** METHOD: sqlite3_changeset_iter 11955 ** 11956 ** The pIter argument passed to this function may either be an iterator 11957 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11958 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11959 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11960 ** is not the case, this function returns [SQLITE_MISUSE]. 11961 ** 11962 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11963 ** outputs are set through these pointers: 11964 ** 11965 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11966 ** depending on the type of change that the iterator currently points to; 11967 ** 11968 ** *pnCol is set to the number of columns in the table affected by the change; and 11969 ** 11970 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11971 ** the name of the table affected by the current change. The buffer remains 11972 ** valid until either sqlite3changeset_next() is called on the iterator 11973 ** or until the conflict-handler function returns. 11974 ** 11975 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11976 ** is an indirect change, or false (0) otherwise. See the documentation for 11977 ** [sqlite3session_indirect()] for a description of direct and indirect 11978 ** changes. 11979 ** 11980 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11981 ** SQLite error code is returned. The values of the output variables may not 11982 ** be trusted in this case. 11983 */ 11984 SQLITE_API int sqlite3changeset_op( 11985 sqlite3_changeset_iter *pIter, /* Iterator object */ 11986 const char **pzTab, /* OUT: Pointer to table name */ 11987 int *pnCol, /* OUT: Number of columns in table */ 11988 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11989 int *pbIndirect /* OUT: True for an 'indirect' change */ 11990 ); 11991 11992 /* 11993 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11994 ** METHOD: sqlite3_changeset_iter 11995 ** 11996 ** For each modified table, a changeset includes the following: 11997 ** 11998 ** <ul> 11999 ** <li> The number of columns in the table, and 12000 ** <li> Which of those columns make up the tables PRIMARY KEY. 12001 ** </ul> 12002 ** 12003 ** This function is used to find which columns comprise the PRIMARY KEY of 12004 ** the table modified by the change that iterator pIter currently points to. 12005 ** If successful, *pabPK is set to point to an array of nCol entries, where 12006 ** nCol is the number of columns in the table. Elements of *pabPK are set to 12007 ** 0x01 if the corresponding column is part of the tables primary key, or 12008 ** 0x00 if it is not. 12009 ** 12010 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 12011 ** in the table. 12012 ** 12013 ** If this function is called when the iterator does not point to a valid 12014 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 12015 ** SQLITE_OK is returned and the output variables populated as described 12016 ** above. 12017 */ 12018 SQLITE_API int sqlite3changeset_pk( 12019 sqlite3_changeset_iter *pIter, /* Iterator object */ 12020 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 12021 int *pnCol /* OUT: Number of entries in output array */ 12022 ); 12023 12024 /* 12025 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 12026 ** METHOD: sqlite3_changeset_iter 12027 ** 12028 ** The pIter argument passed to this function may either be an iterator 12029 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 12030 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 12031 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 12032 ** Furthermore, it may only be called if the type of change that the iterator 12033 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 12034 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 12035 ** 12036 ** Argument iVal must be greater than or equal to 0, and less than the number 12037 ** of columns in the table affected by the current change. Otherwise, 12038 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 12039 ** 12040 ** If successful, this function sets *ppValue to point to a protected 12041 ** sqlite3_value object containing the iVal'th value from the vector of 12042 ** original row values stored as part of the UPDATE or DELETE change and 12043 ** returns SQLITE_OK. The name of the function comes from the fact that this 12044 ** is similar to the "old.*" columns available to update or delete triggers. 12045 ** 12046 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 12047 ** is returned and *ppValue is set to NULL. 12048 */ 12049 SQLITE_API int sqlite3changeset_old( 12050 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 12051 int iVal, /* Column number */ 12052 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 12053 ); 12054 12055 /* 12056 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 12057 ** METHOD: sqlite3_changeset_iter 12058 ** 12059 ** The pIter argument passed to this function may either be an iterator 12060 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 12061 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 12062 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 12063 ** Furthermore, it may only be called if the type of change that the iterator 12064 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 12065 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 12066 ** 12067 ** Argument iVal must be greater than or equal to 0, and less than the number 12068 ** of columns in the table affected by the current change. Otherwise, 12069 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 12070 ** 12071 ** If successful, this function sets *ppValue to point to a protected 12072 ** sqlite3_value object containing the iVal'th value from the vector of 12073 ** new row values stored as part of the UPDATE or INSERT change and 12074 ** returns SQLITE_OK. If the change is an UPDATE and does not include 12075 ** a new value for the requested column, *ppValue is set to NULL and 12076 ** SQLITE_OK returned. The name of the function comes from the fact that 12077 ** this is similar to the "new.*" columns available to update or delete 12078 ** triggers. 12079 ** 12080 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 12081 ** is returned and *ppValue is set to NULL. 12082 */ 12083 SQLITE_API int sqlite3changeset_new( 12084 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 12085 int iVal, /* Column number */ 12086 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 12087 ); 12088 12089 /* 12090 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 12091 ** METHOD: sqlite3_changeset_iter 12092 ** 12093 ** This function should only be used with iterator objects passed to a 12094 ** conflict-handler callback by [sqlite3changeset_apply()] with either 12095 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 12096 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 12097 ** is set to NULL. 12098 ** 12099 ** Argument iVal must be greater than or equal to 0, and less than the number 12100 ** of columns in the table affected by the current change. Otherwise, 12101 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 12102 ** 12103 ** If successful, this function sets *ppValue to point to a protected 12104 ** sqlite3_value object containing the iVal'th value from the 12105 ** "conflicting row" associated with the current conflict-handler callback 12106 ** and returns SQLITE_OK. 12107 ** 12108 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 12109 ** is returned and *ppValue is set to NULL. 12110 */ 12111 SQLITE_API int sqlite3changeset_conflict( 12112 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 12113 int iVal, /* Column number */ 12114 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 12115 ); 12116 12117 /* 12118 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 12119 ** METHOD: sqlite3_changeset_iter 12120 ** 12121 ** This function may only be called with an iterator passed to an 12122 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 12123 ** it sets the output variable to the total number of known foreign key 12124 ** violations in the destination database and returns SQLITE_OK. 12125 ** 12126 ** In all other cases this function returns SQLITE_MISUSE. 12127 */ 12128 SQLITE_API int sqlite3changeset_fk_conflicts( 12129 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 12130 int *pnOut /* OUT: Number of FK violations */ 12131 ); 12132 12133 12134 /* 12135 ** CAPI3REF: Finalize A Changeset Iterator 12136 ** METHOD: sqlite3_changeset_iter 12137 ** 12138 ** This function is used to finalize an iterator allocated with 12139 ** [sqlite3changeset_start()]. 12140 ** 12141 ** This function should only be called on iterators created using the 12142 ** [sqlite3changeset_start()] function. If an application calls this 12143 ** function with an iterator passed to a conflict-handler by 12144 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 12145 ** call has no effect. 12146 ** 12147 ** If an error was encountered within a call to an sqlite3changeset_xxx() 12148 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 12149 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 12150 ** to that error is returned by this function. Otherwise, SQLITE_OK is 12151 ** returned. This is to allow the following pattern (pseudo-code): 12152 ** 12153 ** <pre> 12154 ** sqlite3changeset_start(); 12155 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 12156 ** // Do something with change. 12157 ** } 12158 ** rc = sqlite3changeset_finalize(); 12159 ** if( rc!=SQLITE_OK ){ 12160 ** // An error has occurred 12161 ** } 12162 ** </pre> 12163 */ 12164 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 12165 12166 /* 12167 ** CAPI3REF: Invert A Changeset 12168 ** 12169 ** This function is used to "invert" a changeset object. Applying an inverted 12170 ** changeset to a database reverses the effects of applying the uninverted 12171 ** changeset. Specifically: 12172 ** 12173 ** <ul> 12174 ** <li> Each DELETE change is changed to an INSERT, and 12175 ** <li> Each INSERT change is changed to a DELETE, and 12176 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 12177 ** </ul> 12178 ** 12179 ** This function does not change the order in which changes appear within 12180 ** the changeset. It merely reverses the sense of each individual change. 12181 ** 12182 ** If successful, a pointer to a buffer containing the inverted changeset 12183 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 12184 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 12185 ** zeroed and an SQLite error code returned. 12186 ** 12187 ** It is the responsibility of the caller to eventually call sqlite3_free() 12188 ** on the *ppOut pointer to free the buffer allocation following a successful 12189 ** call to this function. 12190 ** 12191 ** WARNING/TODO: This function currently assumes that the input is a valid 12192 ** changeset. If it is not, the results are undefined. 12193 */ 12194 SQLITE_API int sqlite3changeset_invert( 12195 int nIn, const void *pIn, /* Input changeset */ 12196 int *pnOut, void **ppOut /* OUT: Inverse of input */ 12197 ); 12198 12199 /* 12200 ** CAPI3REF: Concatenate Two Changeset Objects 12201 ** 12202 ** This function is used to concatenate two changesets, A and B, into a 12203 ** single changeset. The result is a changeset equivalent to applying 12204 ** changeset A followed by changeset B. 12205 ** 12206 ** This function combines the two input changesets using an 12207 ** sqlite3_changegroup object. Calling it produces similar results as the 12208 ** following code fragment: 12209 ** 12210 ** <pre> 12211 ** sqlite3_changegroup *pGrp; 12212 ** rc = sqlite3_changegroup_new(&pGrp); 12213 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 12214 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 12215 ** if( rc==SQLITE_OK ){ 12216 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 12217 ** }else{ 12218 ** *ppOut = 0; 12219 ** *pnOut = 0; 12220 ** } 12221 ** </pre> 12222 ** 12223 ** Refer to the sqlite3_changegroup documentation below for details. 12224 */ 12225 SQLITE_API int sqlite3changeset_concat( 12226 int nA, /* Number of bytes in buffer pA */ 12227 void *pA, /* Pointer to buffer containing changeset A */ 12228 int nB, /* Number of bytes in buffer pB */ 12229 void *pB, /* Pointer to buffer containing changeset B */ 12230 int *pnOut, /* OUT: Number of bytes in output changeset */ 12231 void **ppOut /* OUT: Buffer containing output changeset */ 12232 ); 12233 12234 /* 12235 ** CAPI3REF: Changegroup Handle 12236 ** 12237 ** A changegroup is an object used to combine two or more 12238 ** [changesets] or [patchsets] 12239 */ 12240 typedef struct sqlite3_changegroup sqlite3_changegroup; 12241 12242 /* 12243 ** CAPI3REF: Create A New Changegroup Object 12244 ** CONSTRUCTOR: sqlite3_changegroup 12245 ** 12246 ** An sqlite3_changegroup object is used to combine two or more changesets 12247 ** (or patchsets) into a single changeset (or patchset). A single changegroup 12248 ** object may combine changesets or patchsets, but not both. The output is 12249 ** always in the same format as the input. 12250 ** 12251 ** If successful, this function returns SQLITE_OK and populates (*pp) with 12252 ** a pointer to a new sqlite3_changegroup object before returning. The caller 12253 ** should eventually free the returned object using a call to 12254 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 12255 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 12256 ** 12257 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 12258 ** 12259 ** <ul> 12260 ** <li> It is created using a call to sqlite3changegroup_new(). 12261 ** 12262 ** <li> Zero or more changesets (or patchsets) are added to the object 12263 ** by calling sqlite3changegroup_add(). 12264 ** 12265 ** <li> The result of combining all input changesets together is obtained 12266 ** by the application via a call to sqlite3changegroup_output(). 12267 ** 12268 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 12269 ** </ul> 12270 ** 12271 ** Any number of calls to add() and output() may be made between the calls to 12272 ** new() and delete(), and in any order. 12273 ** 12274 ** As well as the regular sqlite3changegroup_add() and 12275 ** sqlite3changegroup_output() functions, also available are the streaming 12276 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 12277 */ 12278 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 12279 12280 /* 12281 ** CAPI3REF: Add a Schema to a Changegroup 12282 ** METHOD: sqlite3_changegroup_schema 12283 ** 12284 ** This method may be used to optionally enforce the rule that the changesets 12285 ** added to the changegroup handle must match the schema of database zDb 12286 ** ("main", "temp", or the name of an attached database). If 12287 ** sqlite3changegroup_add() is called to add a changeset that is not compatible 12288 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup 12289 ** object is left in an undefined state. 12290 ** 12291 ** A changeset schema is considered compatible with the database schema in 12292 ** the same way as for sqlite3changeset_apply(). Specifically, for each 12293 ** table in the changeset, there exists a database table with: 12294 ** 12295 ** <ul> 12296 ** <li> The name identified by the changeset, and 12297 ** <li> at least as many columns as recorded in the changeset, and 12298 ** <li> the primary key columns in the same position as recorded in 12299 ** the changeset. 12300 ** </ul> 12301 ** 12302 ** The output of the changegroup object always has the same schema as the 12303 ** database nominated using this function. In cases where changesets passed 12304 ** to sqlite3changegroup_add() have fewer columns than the corresponding table 12305 ** in the database schema, these are filled in using the default column 12306 ** values from the database schema. This makes it possible to combined 12307 ** changesets that have different numbers of columns for a single table 12308 ** within a changegroup, provided that they are otherwise compatible. 12309 */ 12310 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb); 12311 12312 /* 12313 ** CAPI3REF: Add A Changeset To A Changegroup 12314 ** METHOD: sqlite3_changegroup 12315 ** 12316 ** Add all changes within the changeset (or patchset) in buffer pData (size 12317 ** nData bytes) to the changegroup. 12318 ** 12319 ** If the buffer contains a patchset, then all prior calls to this function 12320 ** on the same changegroup object must also have specified patchsets. Or, if 12321 ** the buffer contains a changeset, so must have the earlier calls to this 12322 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 12323 ** to the changegroup. 12324 ** 12325 ** Rows within the changeset and changegroup are identified by the values in 12326 ** their PRIMARY KEY columns. A change in the changeset is considered to 12327 ** apply to the same row as a change already present in the changegroup if 12328 ** the two rows have the same primary key. 12329 ** 12330 ** Changes to rows that do not already appear in the changegroup are 12331 ** simply copied into it. Or, if both the new changeset and the changegroup 12332 ** contain changes that apply to a single row, the final contents of the 12333 ** changegroup depends on the type of each change, as follows: 12334 ** 12335 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12336 ** <tr><th style="white-space:pre">Existing Change </th> 12337 ** <th style="white-space:pre">New Change </th> 12338 ** <th>Output Change 12339 ** <tr><td>INSERT <td>INSERT <td> 12340 ** The new change is ignored. This case does not occur if the new 12341 ** changeset was recorded immediately after the changesets already 12342 ** added to the changegroup. 12343 ** <tr><td>INSERT <td>UPDATE <td> 12344 ** The INSERT change remains in the changegroup. The values in the 12345 ** INSERT change are modified as if the row was inserted by the 12346 ** existing change and then updated according to the new change. 12347 ** <tr><td>INSERT <td>DELETE <td> 12348 ** The existing INSERT is removed from the changegroup. The DELETE is 12349 ** not added. 12350 ** <tr><td>UPDATE <td>INSERT <td> 12351 ** The new change is ignored. This case does not occur if the new 12352 ** changeset was recorded immediately after the changesets already 12353 ** added to the changegroup. 12354 ** <tr><td>UPDATE <td>UPDATE <td> 12355 ** The existing UPDATE remains within the changegroup. It is amended 12356 ** so that the accompanying values are as if the row was updated once 12357 ** by the existing change and then again by the new change. 12358 ** <tr><td>UPDATE <td>DELETE <td> 12359 ** The existing UPDATE is replaced by the new DELETE within the 12360 ** changegroup. 12361 ** <tr><td>DELETE <td>INSERT <td> 12362 ** If one or more of the column values in the row inserted by the 12363 ** new change differ from those in the row deleted by the existing 12364 ** change, the existing DELETE is replaced by an UPDATE within the 12365 ** changegroup. Otherwise, if the inserted row is exactly the same 12366 ** as the deleted row, the existing DELETE is simply discarded. 12367 ** <tr><td>DELETE <td>UPDATE <td> 12368 ** The new change is ignored. This case does not occur if the new 12369 ** changeset was recorded immediately after the changesets already 12370 ** added to the changegroup. 12371 ** <tr><td>DELETE <td>DELETE <td> 12372 ** The new change is ignored. This case does not occur if the new 12373 ** changeset was recorded immediately after the changesets already 12374 ** added to the changegroup. 12375 ** </table> 12376 ** 12377 ** If the new changeset contains changes to a table that is already present 12378 ** in the changegroup, then the number of columns and the position of the 12379 ** primary key columns for the table must be consistent. If this is not the 12380 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup 12381 ** object has been configured with a database schema using the 12382 ** sqlite3changegroup_schema() API, then it is possible to combine changesets 12383 ** with different numbers of columns for a single table, provided that 12384 ** they are otherwise compatible. 12385 ** 12386 ** If the input changeset appears to be corrupt and the corruption is 12387 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition 12388 ** occurs during processing, this function returns SQLITE_NOMEM. 12389 ** 12390 ** In all cases, if an error occurs the state of the final contents of the 12391 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned. 12392 */ 12393 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 12394 12395 /* 12396 ** CAPI3REF: Add A Single Change To A Changegroup 12397 ** METHOD: sqlite3_changegroup 12398 ** 12399 ** This function adds the single change currently indicated by the iterator 12400 ** passed as the second argument to the changegroup object. The rules for 12401 ** adding the change are just as described for [sqlite3changegroup_add()]. 12402 ** 12403 ** If the change is successfully added to the changegroup, SQLITE_OK is 12404 ** returned. Otherwise, an SQLite error code is returned. 12405 ** 12406 ** The iterator must point to a valid entry when this function is called. 12407 ** If it does not, SQLITE_ERROR is returned and no change is added to the 12408 ** changegroup. Additionally, the iterator must not have been opened with 12409 ** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also 12410 ** returned. 12411 */ 12412 SQLITE_API int sqlite3changegroup_add_change( 12413 sqlite3_changegroup*, 12414 sqlite3_changeset_iter* 12415 ); 12416 12417 12418 12419 /* 12420 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 12421 ** METHOD: sqlite3_changegroup 12422 ** 12423 ** Obtain a buffer containing a changeset (or patchset) representing the 12424 ** current contents of the changegroup. If the inputs to the changegroup 12425 ** were themselves changesets, the output is a changeset. Or, if the 12426 ** inputs were patchsets, the output is also a patchset. 12427 ** 12428 ** As with the output of the sqlite3session_changeset() and 12429 ** sqlite3session_patchset() functions, all changes related to a single 12430 ** table are grouped together in the output of this function. Tables appear 12431 ** in the same order as for the very first changeset added to the changegroup. 12432 ** If the second or subsequent changesets added to the changegroup contain 12433 ** changes for tables that do not appear in the first changeset, they are 12434 ** appended onto the end of the output changeset, again in the order in 12435 ** which they are first encountered. 12436 ** 12437 ** If an error occurs, an SQLite error code is returned and the output 12438 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 12439 ** is returned and the output variables are set to the size of and a 12440 ** pointer to the output buffer, respectively. In this case it is the 12441 ** responsibility of the caller to eventually free the buffer using a 12442 ** call to sqlite3_free(). 12443 */ 12444 SQLITE_API int sqlite3changegroup_output( 12445 sqlite3_changegroup*, 12446 int *pnData, /* OUT: Size of output buffer in bytes */ 12447 void **ppData /* OUT: Pointer to output buffer */ 12448 ); 12449 12450 /* 12451 ** CAPI3REF: Delete A Changegroup Object 12452 ** DESTRUCTOR: sqlite3_changegroup 12453 */ 12454 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 12455 12456 /* 12457 ** CAPI3REF: Apply A Changeset To A Database 12458 ** 12459 ** Apply a changeset or patchset to a database. These functions attempt to 12460 ** update the "main" database attached to handle db with the changes found in 12461 ** the changeset passed via the second and third arguments. 12462 ** 12463 ** All changes made by these functions are enclosed in a savepoint transaction. 12464 ** If any other error (aside from a constraint failure when attempting to 12465 ** write to the target database) occurs, then the savepoint transaction is 12466 ** rolled back, restoring the target database to its original state, and an 12467 ** SQLite error code returned. Additionally, starting with version 3.51.0, 12468 ** an error code and error message that may be accessed using the 12469 ** [sqlite3_errcode()] and [sqlite3_errmsg()] APIs are left in the database 12470 ** handle. 12471 ** 12472 ** The fourth argument (xFilter) passed to these functions is the "filter 12473 ** callback". This may be passed NULL, in which case all changes in the 12474 ** changeset are applied to the database. For sqlite3changeset_apply() and 12475 ** sqlite3_changeset_apply_v2(), if it is not NULL, then it is invoked once 12476 ** for each table affected by at least one change in the changeset. In this 12477 ** case the table name is passed as the second argument, and a copy of 12478 ** the context pointer passed as the sixth argument to apply() or apply_v2() 12479 ** as the first. If the "filter callback" returns zero, then no attempt is 12480 ** made to apply any changes to the table. Otherwise, if the return value is 12481 ** non-zero, all changes related to the table are attempted. 12482 ** 12483 ** For sqlite3_changeset_apply_v3(), the xFilter callback is invoked once 12484 ** per change. The second argument in this case is an sqlite3_changeset_iter 12485 ** that may be queried using the usual APIs for the details of the current 12486 ** change. If the "filter callback" returns zero in this case, then no attempt 12487 ** is made to apply the current change. If it returns non-zero, the change 12488 ** is applied. 12489 ** 12490 ** For each table that is not excluded by the filter callback, this function 12491 ** tests that the target database contains a compatible table. A table is 12492 ** considered compatible if all of the following are true: 12493 ** 12494 ** <ul> 12495 ** <li> The table has the same name as the name recorded in the 12496 ** changeset, and 12497 ** <li> The table has at least as many columns as recorded in the 12498 ** changeset, and 12499 ** <li> The table has primary key columns in the same position as 12500 ** recorded in the changeset. 12501 ** </ul> 12502 ** 12503 ** If there is no compatible table, it is not an error, but none of the 12504 ** changes associated with the table are applied. A warning message is issued 12505 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 12506 ** one such warning is issued for each table in the changeset. 12507 ** 12508 ** For each change for which there is a compatible table, an attempt is made 12509 ** to modify the table contents according to each UPDATE, INSERT or DELETE 12510 ** change that is not excluded by a filter callback. If a change cannot be 12511 ** applied cleanly, the conflict handler function passed as the fifth argument 12512 ** to sqlite3changeset_apply() may be invoked. A description of exactly when 12513 ** the conflict handler is invoked for each type of change is below. 12514 ** 12515 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 12516 ** of passing anything other than a valid function pointer as the xConflict 12517 ** argument are undefined. 12518 ** 12519 ** Each time the conflict handler function is invoked, it must return one 12520 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 12521 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 12522 ** if the second argument passed to the conflict handler is either 12523 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 12524 ** returns an illegal value, any changes already made are rolled back and 12525 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 12526 ** actions are taken by sqlite3changeset_apply() depending on the value 12527 ** returned by each invocation of the conflict-handler function. Refer to 12528 ** the documentation for the three 12529 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 12530 ** 12531 ** <dl> 12532 ** <dt>DELETE Changes<dd> 12533 ** For each DELETE change, the function checks if the target database 12534 ** contains a row with the same primary key value (or values) as the 12535 ** original row values stored in the changeset. If it does, and the values 12536 ** stored in all non-primary key columns also match the values stored in 12537 ** the changeset the row is deleted from the target database. 12538 ** 12539 ** If a row with matching primary key values is found, but one or more of 12540 ** the non-primary key fields contains a value different from the original 12541 ** row value stored in the changeset, the conflict-handler function is 12542 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 12543 ** database table has more columns than are recorded in the changeset, 12544 ** only the values of those non-primary key fields are compared against 12545 ** the current database contents - any trailing database table columns 12546 ** are ignored. 12547 ** 12548 ** If no row with matching primary key values is found in the database, 12549 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12550 ** passed as the second argument. 12551 ** 12552 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 12553 ** (which can only happen if a foreign key constraint is violated), the 12554 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 12555 ** passed as the second argument. This includes the case where the DELETE 12556 ** operation is attempted because an earlier call to the conflict handler 12557 ** function returned [SQLITE_CHANGESET_REPLACE]. 12558 ** 12559 ** <dt>INSERT Changes<dd> 12560 ** For each INSERT change, an attempt is made to insert the new row into 12561 ** the database. If the changeset row contains fewer fields than the 12562 ** database table, the trailing fields are populated with their default 12563 ** values. 12564 ** 12565 ** If the attempt to insert the row fails because the database already 12566 ** contains a row with the same primary key values, the conflict handler 12567 ** function is invoked with the second argument set to 12568 ** [SQLITE_CHANGESET_CONFLICT]. 12569 ** 12570 ** If the attempt to insert the row fails because of some other constraint 12571 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 12572 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 12573 ** This includes the case where the INSERT operation is re-attempted because 12574 ** an earlier call to the conflict handler function returned 12575 ** [SQLITE_CHANGESET_REPLACE]. 12576 ** 12577 ** <dt>UPDATE Changes<dd> 12578 ** For each UPDATE change, the function checks if the target database 12579 ** contains a row with the same primary key value (or values) as the 12580 ** original row values stored in the changeset. If it does, and the values 12581 ** stored in all modified non-primary key columns also match the values 12582 ** stored in the changeset the row is updated within the target database. 12583 ** 12584 ** If a row with matching primary key values is found, but one or more of 12585 ** the modified non-primary key fields contains a value different from an 12586 ** original row value stored in the changeset, the conflict-handler function 12587 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 12588 ** UPDATE changes only contain values for non-primary key fields that are 12589 ** to be modified, only those fields need to match the original values to 12590 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 12591 ** 12592 ** If no row with matching primary key values is found in the database, 12593 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12594 ** passed as the second argument. 12595 ** 12596 ** If the UPDATE operation is attempted, but SQLite returns 12597 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 12598 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 12599 ** This includes the case where the UPDATE operation is attempted after 12600 ** an earlier call to the conflict handler function returned 12601 ** [SQLITE_CHANGESET_REPLACE]. 12602 ** </dl> 12603 ** 12604 ** It is safe to execute SQL statements, including those that write to the 12605 ** table that the callback related to, from within the xConflict callback. 12606 ** This can be used to further customize the application's conflict 12607 ** resolution strategy. 12608 ** 12609 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 12610 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 12611 ** may set (*ppRebase) to point to a "rebase" that may be used with the 12612 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 12613 ** is set to the size of the buffer in bytes. It is the responsibility of the 12614 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 12615 ** is only allocated and populated if one or more conflicts were encountered 12616 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 12617 ** APIs for further details. 12618 ** 12619 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 12620 ** may be modified by passing a combination of 12621 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 12622 ** 12623 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 12624 ** and therefore subject to change. 12625 */ 12626 SQLITE_API int sqlite3changeset_apply( 12627 sqlite3 *db, /* Apply change to "main" db of this handle */ 12628 int nChangeset, /* Size of changeset in bytes */ 12629 void *pChangeset, /* Changeset blob */ 12630 int(*xFilter)( 12631 void *pCtx, /* Copy of sixth arg to _apply() */ 12632 const char *zTab /* Table name */ 12633 ), 12634 int(*xConflict)( 12635 void *pCtx, /* Copy of sixth arg to _apply() */ 12636 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12637 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12638 ), 12639 void *pCtx /* First argument passed to xConflict */ 12640 ); 12641 SQLITE_API int sqlite3changeset_apply_v2( 12642 sqlite3 *db, /* Apply change to "main" db of this handle */ 12643 int nChangeset, /* Size of changeset in bytes */ 12644 void *pChangeset, /* Changeset blob */ 12645 int(*xFilter)( 12646 void *pCtx, /* Copy of sixth arg to _apply() */ 12647 const char *zTab /* Table name */ 12648 ), 12649 int(*xConflict)( 12650 void *pCtx, /* Copy of sixth arg to _apply() */ 12651 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12652 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12653 ), 12654 void *pCtx, /* First argument passed to xConflict */ 12655 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 12656 int flags /* SESSION_CHANGESETAPPLY_* flags */ 12657 ); 12658 SQLITE_API int sqlite3changeset_apply_v3( 12659 sqlite3 *db, /* Apply change to "main" db of this handle */ 12660 int nChangeset, /* Size of changeset in bytes */ 12661 void *pChangeset, /* Changeset blob */ 12662 int(*xFilter)( 12663 void *pCtx, /* Copy of sixth arg to _apply() */ 12664 sqlite3_changeset_iter *p /* Handle describing change */ 12665 ), 12666 int(*xConflict)( 12667 void *pCtx, /* Copy of sixth arg to _apply() */ 12668 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12669 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12670 ), 12671 void *pCtx, /* First argument passed to xConflict */ 12672 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 12673 int flags /* SESSION_CHANGESETAPPLY_* flags */ 12674 ); 12675 12676 /* 12677 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 12678 ** 12679 ** The following flags may passed via the 9th parameter to 12680 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 12681 ** 12682 ** <dl> 12683 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 12684 ** Usually, the sessions module encloses all operations performed by 12685 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 12686 ** SAVEPOINT is committed if the changeset or patchset is successfully 12687 ** applied, or rolled back if an error occurs. Specifying this flag 12688 ** causes the sessions module to omit this savepoint. In this case, if the 12689 ** caller has an open transaction or savepoint when apply_v2() is called, 12690 ** it may revert the partially applied changeset by rolling it back. 12691 ** 12692 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 12693 ** Invert the changeset before applying it. This is equivalent to inverting 12694 ** a changeset using sqlite3changeset_invert() before applying it. It is 12695 ** an error to specify this flag with a patchset. 12696 ** 12697 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd> 12698 ** Do not invoke the conflict handler callback for any changes that 12699 ** would not actually modify the database even if they were applied. 12700 ** Specifically, this means that the conflict handler is not invoked 12701 ** for: 12702 ** <ul> 12703 ** <li>a delete change if the row being deleted cannot be found, 12704 ** <li>an update change if the modified fields are already set to 12705 ** their new values in the conflicting row, or 12706 ** <li>an insert change if all fields of the conflicting row match 12707 ** the row being inserted. 12708 ** </ul> 12709 ** 12710 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd> 12711 ** If this flag it set, then all foreign key constraints in the target 12712 ** database behave as if they were declared with "ON UPDATE NO ACTION ON 12713 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL 12714 ** or SET DEFAULT. 12715 */ 12716 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 12717 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 12718 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004 12719 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008 12720 12721 /* 12722 ** CAPI3REF: Constants Passed To The Conflict Handler 12723 ** 12724 ** Values that may be passed as the second argument to a conflict-handler. 12725 ** 12726 ** <dl> 12727 ** <dt>SQLITE_CHANGESET_DATA<dd> 12728 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 12729 ** when processing a DELETE or UPDATE change if a row with the required 12730 ** PRIMARY KEY fields is present in the database, but one or more other 12731 ** (non primary-key) fields modified by the update do not contain the 12732 ** expected "before" values. 12733 ** 12734 ** The conflicting row, in this case, is the database row with the matching 12735 ** primary key. 12736 ** 12737 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 12738 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 12739 ** argument when processing a DELETE or UPDATE change if a row with the 12740 ** required PRIMARY KEY fields is not present in the database. 12741 ** 12742 ** There is no conflicting row in this case. The results of invoking the 12743 ** sqlite3changeset_conflict() API are undefined. 12744 ** 12745 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 12746 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 12747 ** handler while processing an INSERT change if the operation would result 12748 ** in duplicate primary key values. 12749 ** 12750 ** The conflicting row in this case is the database row with the matching 12751 ** primary key. 12752 ** 12753 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 12754 ** If foreign key handling is enabled, and applying a changeset leaves the 12755 ** database in a state containing foreign key violations, the conflict 12756 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 12757 ** exactly once before the changeset is committed. If the conflict handler 12758 ** returns CHANGESET_OMIT, the changes, including those that caused the 12759 ** foreign key constraint violation, are committed. Or, if it returns 12760 ** CHANGESET_ABORT, the changeset is rolled back. 12761 ** 12762 ** No current or conflicting row information is provided. The only function 12763 ** it is possible to call on the supplied sqlite3_changeset_iter handle 12764 ** is sqlite3changeset_fk_conflicts(). 12765 ** 12766 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 12767 ** If any other constraint violation occurs while applying a change (i.e. 12768 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 12769 ** invoked with CHANGESET_CONSTRAINT as the second argument. 12770 ** 12771 ** There is no conflicting row in this case. The results of invoking the 12772 ** sqlite3changeset_conflict() API are undefined. 12773 ** 12774 ** </dl> 12775 */ 12776 #define SQLITE_CHANGESET_DATA 1 12777 #define SQLITE_CHANGESET_NOTFOUND 2 12778 #define SQLITE_CHANGESET_CONFLICT 3 12779 #define SQLITE_CHANGESET_CONSTRAINT 4 12780 #define SQLITE_CHANGESET_FOREIGN_KEY 5 12781 12782 /* 12783 ** CAPI3REF: Constants Returned By The Conflict Handler 12784 ** 12785 ** A conflict handler callback must return one of the following three values. 12786 ** 12787 ** <dl> 12788 ** <dt>SQLITE_CHANGESET_OMIT<dd> 12789 ** If a conflict handler returns this value no special action is taken. The 12790 ** change that caused the conflict is not applied. The session module 12791 ** continues to the next change in the changeset. 12792 ** 12793 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 12794 ** This value may only be returned if the second argument to the conflict 12795 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 12796 ** is not the case, any changes applied so far are rolled back and the 12797 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 12798 ** 12799 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 12800 ** handler, then the conflicting row is either updated or deleted, depending 12801 ** on the type of change. 12802 ** 12803 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 12804 ** handler, then the conflicting row is removed from the database and a 12805 ** second attempt to apply the change is made. If this second attempt fails, 12806 ** the original row is restored to the database before continuing. 12807 ** 12808 ** <dt>SQLITE_CHANGESET_ABORT<dd> 12809 ** If this value is returned, any changes applied so far are rolled back 12810 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 12811 ** </dl> 12812 */ 12813 #define SQLITE_CHANGESET_OMIT 0 12814 #define SQLITE_CHANGESET_REPLACE 1 12815 #define SQLITE_CHANGESET_ABORT 2 12816 12817 /* 12818 ** CAPI3REF: Rebasing changesets 12819 ** EXPERIMENTAL 12820 ** 12821 ** Suppose there is a site hosting a database in state S0. And that 12822 ** modifications are made that move that database to state S1 and a 12823 ** changeset recorded (the "local" changeset). Then, a changeset based 12824 ** on S0 is received from another site (the "remote" changeset) and 12825 ** applied to the database. The database is then in state 12826 ** (S1+"remote"), where the exact state depends on any conflict 12827 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 12828 ** Rebasing a changeset is to update it to take those conflict 12829 ** resolution decisions into account, so that the same conflicts 12830 ** do not have to be resolved elsewhere in the network. 12831 ** 12832 ** For example, if both the local and remote changesets contain an 12833 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 12834 ** 12835 ** local: INSERT INTO t1 VALUES(1, 'v1'); 12836 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 12837 ** 12838 ** and the conflict resolution is REPLACE, then the INSERT change is 12839 ** removed from the local changeset (it was overridden). Or, if the 12840 ** conflict resolution was "OMIT", then the local changeset is modified 12841 ** to instead contain: 12842 ** 12843 ** UPDATE t1 SET b = 'v2' WHERE a=1; 12844 ** 12845 ** Changes within the local changeset are rebased as follows: 12846 ** 12847 ** <dl> 12848 ** <dt>Local INSERT<dd> 12849 ** This may only conflict with a remote INSERT. If the conflict 12850 ** resolution was OMIT, then add an UPDATE change to the rebased 12851 ** changeset. Or, if the conflict resolution was REPLACE, add 12852 ** nothing to the rebased changeset. 12853 ** 12854 ** <dt>Local DELETE<dd> 12855 ** This may conflict with a remote UPDATE or DELETE. In both cases the 12856 ** only possible resolution is OMIT. If the remote operation was a 12857 ** DELETE, then add no change to the rebased changeset. If the remote 12858 ** operation was an UPDATE, then the old.* fields of change are updated 12859 ** to reflect the new.* values in the UPDATE. 12860 ** 12861 ** <dt>Local UPDATE<dd> 12862 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 12863 ** with a DELETE, and the conflict resolution was OMIT, then the update 12864 ** is changed into an INSERT. Any undefined values in the new.* record 12865 ** from the update change are filled in using the old.* values from 12866 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 12867 ** the UPDATE change is simply omitted from the rebased changeset. 12868 ** 12869 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 12870 ** the old.* values are rebased using the new.* values in the remote 12871 ** change. Or, if the resolution is REPLACE, then the change is copied 12872 ** into the rebased changeset with updates to columns also updated by 12873 ** the conflicting remote UPDATE removed. If this means no columns would 12874 ** be updated, the change is omitted. 12875 ** </dl> 12876 ** 12877 ** A local change may be rebased against multiple remote changes 12878 ** simultaneously. If a single key is modified by multiple remote 12879 ** changesets, they are combined as follows before the local changeset 12880 ** is rebased: 12881 ** 12882 ** <ul> 12883 ** <li> If there has been one or more REPLACE resolutions on a 12884 ** key, it is rebased according to a REPLACE. 12885 ** 12886 ** <li> If there have been no REPLACE resolutions on a key, then 12887 ** the local changeset is rebased according to the most recent 12888 ** of the OMIT resolutions. 12889 ** </ul> 12890 ** 12891 ** Note that conflict resolutions from multiple remote changesets are 12892 ** combined on a per-field basis, not per-row. This means that in the 12893 ** case of multiple remote UPDATE operations, some fields of a single 12894 ** local change may be rebased for REPLACE while others are rebased for 12895 ** OMIT. 12896 ** 12897 ** In order to rebase a local changeset, the remote changeset must first 12898 ** be applied to the local database using sqlite3changeset_apply_v2() and 12899 ** the buffer of rebase information captured. Then: 12900 ** 12901 ** <ol> 12902 ** <li> An sqlite3_rebaser object is created by calling 12903 ** sqlite3rebaser_create(). 12904 ** <li> The new object is configured with the rebase buffer obtained from 12905 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12906 ** If the local changeset is to be rebased against multiple remote 12907 ** changesets, then sqlite3rebaser_configure() should be called 12908 ** multiple times, in the same order that the multiple 12909 ** sqlite3changeset_apply_v2() calls were made. 12910 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12911 ** <li> The sqlite3_rebaser object is deleted by calling 12912 ** sqlite3rebaser_delete(). 12913 ** </ol> 12914 */ 12915 typedef struct sqlite3_rebaser sqlite3_rebaser; 12916 12917 /* 12918 ** CAPI3REF: Create a changeset rebaser object. 12919 ** EXPERIMENTAL 12920 ** 12921 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12922 ** point to the new object and return SQLITE_OK. Otherwise, if an error 12923 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12924 ** to NULL. 12925 */ 12926 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12927 12928 /* 12929 ** CAPI3REF: Configure a changeset rebaser object. 12930 ** EXPERIMENTAL 12931 ** 12932 ** Configure the changeset rebaser object to rebase changesets according 12933 ** to the conflict resolutions described by buffer pRebase (size nRebase 12934 ** bytes), which must have been obtained from a previous call to 12935 ** sqlite3changeset_apply_v2(). 12936 */ 12937 SQLITE_API int sqlite3rebaser_configure( 12938 sqlite3_rebaser*, 12939 int nRebase, const void *pRebase 12940 ); 12941 12942 /* 12943 ** CAPI3REF: Rebase a changeset 12944 ** EXPERIMENTAL 12945 ** 12946 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12947 ** in size. This function allocates and populates a buffer with a copy 12948 ** of the changeset rebased according to the configuration of the 12949 ** rebaser object passed as the first argument. If successful, (*ppOut) 12950 ** is set to point to the new buffer containing the rebased changeset and 12951 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12952 ** responsibility of the caller to eventually free the new buffer using 12953 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12954 ** are set to zero and an SQLite error code returned. 12955 */ 12956 SQLITE_API int sqlite3rebaser_rebase( 12957 sqlite3_rebaser*, 12958 int nIn, const void *pIn, 12959 int *pnOut, void **ppOut 12960 ); 12961 12962 /* 12963 ** CAPI3REF: Delete a changeset rebaser object. 12964 ** EXPERIMENTAL 12965 ** 12966 ** Delete the changeset rebaser object and all associated resources. There 12967 ** should be one call to this function for each successful invocation 12968 ** of sqlite3rebaser_create(). 12969 */ 12970 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12971 12972 /* 12973 ** CAPI3REF: Streaming Versions of API functions. 12974 ** 12975 ** The six streaming API xxx_strm() functions serve similar purposes to the 12976 ** corresponding non-streaming API functions: 12977 ** 12978 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12979 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12980 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12981 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12982 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12983 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12984 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12985 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12986 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12987 ** </table> 12988 ** 12989 ** Non-streaming functions that accept changesets (or patchsets) as input 12990 ** require that the entire changeset be stored in a single buffer in memory. 12991 ** Similarly, those that return a changeset or patchset do so by returning 12992 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12993 ** Normally this is convenient. However, if an application running in a 12994 ** low-memory environment is required to handle very large changesets, the 12995 ** large contiguous memory allocations required can become onerous. 12996 ** 12997 ** In order to avoid this problem, instead of a single large buffer, input 12998 ** is passed to a streaming API functions by way of a callback function that 12999 ** the sessions module invokes to incrementally request input data as it is 13000 ** required. In all cases, a pair of API function parameters such as 13001 ** 13002 ** <pre> 13003 ** int nChangeset, 13004 ** void *pChangeset, 13005 ** </pre> 13006 ** 13007 ** Is replaced by: 13008 ** 13009 ** <pre> 13010 ** int (*xInput)(void *pIn, void *pData, int *pnData), 13011 ** void *pIn, 13012 ** </pre> 13013 ** 13014 ** Each time the xInput callback is invoked by the sessions module, the first 13015 ** argument passed is a copy of the supplied pIn context pointer. The second 13016 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 13017 ** error occurs the xInput method should copy up to (*pnData) bytes of data 13018 ** into the buffer and set (*pnData) to the actual number of bytes copied 13019 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 13020 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 13021 ** error code should be returned. In all cases, if an xInput callback returns 13022 ** an error, all processing is abandoned and the streaming API function 13023 ** returns a copy of the error code to the caller. 13024 ** 13025 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 13026 ** invoked by the sessions module at any point during the lifetime of the 13027 ** iterator. If such an xInput callback returns an error, the iterator enters 13028 ** an error state, whereby all subsequent calls to iterator functions 13029 ** immediately fail with the same error code as returned by xInput. 13030 ** 13031 ** Similarly, streaming API functions that return changesets (or patchsets) 13032 ** return them in chunks by way of a callback function instead of via a 13033 ** pointer to a single large buffer. In this case, a pair of parameters such 13034 ** as: 13035 ** 13036 ** <pre> 13037 ** int *pnChangeset, 13038 ** void **ppChangeset, 13039 ** </pre> 13040 ** 13041 ** Is replaced by: 13042 ** 13043 ** <pre> 13044 ** int (*xOutput)(void *pOut, const void *pData, int nData), 13045 ** void *pOut 13046 ** </pre> 13047 ** 13048 ** The xOutput callback is invoked zero or more times to return data to 13049 ** the application. The first parameter passed to each call is a copy of the 13050 ** pOut pointer supplied by the application. The second parameter, pData, 13051 ** points to a buffer nData bytes in size containing the chunk of output 13052 ** data being returned. If the xOutput callback successfully processes the 13053 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 13054 ** it should return some other SQLite error code. In this case processing 13055 ** is immediately abandoned and the streaming API function returns a copy 13056 ** of the xOutput error code to the application. 13057 ** 13058 ** The sessions module never invokes an xOutput callback with the third 13059 ** parameter set to a value less than or equal to zero. Other than this, 13060 ** no guarantees are made as to the size of the chunks of data returned. 13061 */ 13062 SQLITE_API int sqlite3changeset_apply_strm( 13063 sqlite3 *db, /* Apply change to "main" db of this handle */ 13064 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 13065 void *pIn, /* First arg for xInput */ 13066 int(*xFilter)( 13067 void *pCtx, /* Copy of sixth arg to _apply() */ 13068 const char *zTab /* Table name */ 13069 ), 13070 int(*xConflict)( 13071 void *pCtx, /* Copy of sixth arg to _apply() */ 13072 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 13073 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 13074 ), 13075 void *pCtx /* First argument passed to xConflict */ 13076 ); 13077 SQLITE_API int sqlite3changeset_apply_v2_strm( 13078 sqlite3 *db, /* Apply change to "main" db of this handle */ 13079 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 13080 void *pIn, /* First arg for xInput */ 13081 int(*xFilter)( 13082 void *pCtx, /* Copy of sixth arg to _apply() */ 13083 const char *zTab /* Table name */ 13084 ), 13085 int(*xConflict)( 13086 void *pCtx, /* Copy of sixth arg to _apply() */ 13087 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 13088 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 13089 ), 13090 void *pCtx, /* First argument passed to xConflict */ 13091 void **ppRebase, int *pnRebase, 13092 int flags 13093 ); 13094 SQLITE_API int sqlite3changeset_apply_v3_strm( 13095 sqlite3 *db, /* Apply change to "main" db of this handle */ 13096 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 13097 void *pIn, /* First arg for xInput */ 13098 int(*xFilter)( 13099 void *pCtx, /* Copy of sixth arg to _apply() */ 13100 sqlite3_changeset_iter *p 13101 ), 13102 int(*xConflict)( 13103 void *pCtx, /* Copy of sixth arg to _apply() */ 13104 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 13105 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 13106 ), 13107 void *pCtx, /* First argument passed to xConflict */ 13108 void **ppRebase, int *pnRebase, 13109 int flags 13110 ); 13111 SQLITE_API int sqlite3changeset_concat_strm( 13112 int (*xInputA)(void *pIn, void *pData, int *pnData), 13113 void *pInA, 13114 int (*xInputB)(void *pIn, void *pData, int *pnData), 13115 void *pInB, 13116 int (*xOutput)(void *pOut, const void *pData, int nData), 13117 void *pOut 13118 ); 13119 SQLITE_API int sqlite3changeset_invert_strm( 13120 int (*xInput)(void *pIn, void *pData, int *pnData), 13121 void *pIn, 13122 int (*xOutput)(void *pOut, const void *pData, int nData), 13123 void *pOut 13124 ); 13125 SQLITE_API int sqlite3changeset_start_strm( 13126 sqlite3_changeset_iter **pp, 13127 int (*xInput)(void *pIn, void *pData, int *pnData), 13128 void *pIn 13129 ); 13130 SQLITE_API int sqlite3changeset_start_v2_strm( 13131 sqlite3_changeset_iter **pp, 13132 int (*xInput)(void *pIn, void *pData, int *pnData), 13133 void *pIn, 13134 int flags 13135 ); 13136 SQLITE_API int sqlite3session_changeset_strm( 13137 sqlite3_session *pSession, 13138 int (*xOutput)(void *pOut, const void *pData, int nData), 13139 void *pOut 13140 ); 13141 SQLITE_API int sqlite3session_patchset_strm( 13142 sqlite3_session *pSession, 13143 int (*xOutput)(void *pOut, const void *pData, int nData), 13144 void *pOut 13145 ); 13146 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 13147 int (*xInput)(void *pIn, void *pData, int *pnData), 13148 void *pIn 13149 ); 13150 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 13151 int (*xOutput)(void *pOut, const void *pData, int nData), 13152 void *pOut 13153 ); 13154 SQLITE_API int sqlite3rebaser_rebase_strm( 13155 sqlite3_rebaser *pRebaser, 13156 int (*xInput)(void *pIn, void *pData, int *pnData), 13157 void *pIn, 13158 int (*xOutput)(void *pOut, const void *pData, int nData), 13159 void *pOut 13160 ); 13161 13162 /* 13163 ** CAPI3REF: Configure global parameters 13164 ** 13165 ** The sqlite3session_config() interface is used to make global configuration 13166 ** changes to the sessions module in order to tune it to the specific needs 13167 ** of the application. 13168 ** 13169 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 13170 ** while any other thread is inside any other sessions method then the 13171 ** results are undefined. Furthermore, if it is invoked after any sessions 13172 ** related objects have been created, the results are also undefined. 13173 ** 13174 ** The first argument to the sqlite3session_config() function must be one 13175 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 13176 ** interpretation of the (void*) value passed as the second parameter and 13177 ** the effect of calling this function depends on the value of the first 13178 ** parameter. 13179 ** 13180 ** <dl> 13181 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 13182 ** By default, the sessions module streaming interfaces attempt to input 13183 ** and output data in approximately 1 KiB chunks. This operand may be used 13184 ** to set and query the value of this configuration setting. The pointer 13185 ** passed as the second argument must point to a value of type (int). 13186 ** If this value is greater than 0, it is used as the new streaming data 13187 ** chunk size for both input and output. Before returning, the (int) value 13188 ** pointed to by pArg is set to the final value of the streaming interface 13189 ** chunk size. 13190 ** </dl> 13191 ** 13192 ** This function returns SQLITE_OK if successful, or an SQLite error code 13193 ** otherwise. 13194 */ 13195 SQLITE_API int sqlite3session_config(int op, void *pArg); 13196 13197 /* 13198 ** CAPI3REF: Values for sqlite3session_config(). 13199 */ 13200 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 13201 13202 /* 13203 ** Make sure we can call this stuff from C++. 13204 */ 13205 #ifdef __cplusplus 13206 } 13207 #endif 13208 13209 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 13210 13211 /******** End of sqlite3session.h *********/ 13212 /******** Begin file fts5.h *********/ 13213 /* 13214 ** 2014 May 31 13215 ** 13216 ** The author disclaims copyright to this source code. In place of 13217 ** a legal notice, here is a blessing: 13218 ** 13219 ** May you do good and not evil. 13220 ** May you find forgiveness for yourself and forgive others. 13221 ** May you share freely, never taking more than you give. 13222 ** 13223 ****************************************************************************** 13224 ** 13225 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 13226 ** FTS5 may be extended with: 13227 ** 13228 ** * custom tokenizers, and 13229 ** * custom auxiliary functions. 13230 */ 13231 13232 13233 #ifndef _FTS5_H 13234 #define _FTS5_H 13235 13236 13237 #ifdef __cplusplus 13238 extern "C" { 13239 #endif 13240 13241 /************************************************************************* 13242 ** CUSTOM AUXILIARY FUNCTIONS 13243 ** 13244 ** Virtual table implementations may overload SQL functions by implementing 13245 ** the sqlite3_module.xFindFunction() method. 13246 */ 13247 13248 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 13249 typedef struct Fts5Context Fts5Context; 13250 typedef struct Fts5PhraseIter Fts5PhraseIter; 13251 13252 typedef void (*fts5_extension_function)( 13253 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 13254 Fts5Context *pFts, /* First arg to pass to pApi functions */ 13255 sqlite3_context *pCtx, /* Context for returning result/error */ 13256 int nVal, /* Number of values in apVal[] array */ 13257 sqlite3_value **apVal /* Array of trailing arguments */ 13258 ); 13259 13260 struct Fts5PhraseIter { 13261 const unsigned char *a; 13262 const unsigned char *b; 13263 }; 13264 13265 /* 13266 ** EXTENSION API FUNCTIONS 13267 ** 13268 ** xUserData(pFts): 13269 ** Return a copy of the pUserData pointer passed to the xCreateFunction() 13270 ** API when the extension function was registered. 13271 ** 13272 ** xColumnTotalSize(pFts, iCol, pnToken): 13273 ** If parameter iCol is less than zero, set output variable *pnToken 13274 ** to the total number of tokens in the FTS5 table. Or, if iCol is 13275 ** non-negative but less than the number of columns in the table, return 13276 ** the total number of tokens in column iCol, considering all rows in 13277 ** the FTS5 table. 13278 ** 13279 ** If parameter iCol is greater than or equal to the number of columns 13280 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 13281 ** an OOM condition or IO error), an appropriate SQLite error code is 13282 ** returned. 13283 ** 13284 ** xColumnCount(pFts): 13285 ** Return the number of columns in the table. 13286 ** 13287 ** xColumnSize(pFts, iCol, pnToken): 13288 ** If parameter iCol is less than zero, set output variable *pnToken 13289 ** to the total number of tokens in the current row. Or, if iCol is 13290 ** non-negative but less than the number of columns in the table, set 13291 ** *pnToken to the number of tokens in column iCol of the current row. 13292 ** 13293 ** If parameter iCol is greater than or equal to the number of columns 13294 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 13295 ** an OOM condition or IO error), an appropriate SQLite error code is 13296 ** returned. 13297 ** 13298 ** This function may be quite inefficient if used with an FTS5 table 13299 ** created with the "columnsize=0" option. 13300 ** 13301 ** xColumnText: 13302 ** If parameter iCol is less than zero, or greater than or equal to the 13303 ** number of columns in the table, SQLITE_RANGE is returned. 13304 ** 13305 ** Otherwise, this function attempts to retrieve the text of column iCol of 13306 ** the current document. If successful, (*pz) is set to point to a buffer 13307 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 13308 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 13309 ** if an error occurs, an SQLite error code is returned and the final values 13310 ** of (*pz) and (*pn) are undefined. 13311 ** 13312 ** xPhraseCount: 13313 ** Returns the number of phrases in the current query expression. 13314 ** 13315 ** xPhraseSize: 13316 ** If parameter iCol is less than zero, or greater than or equal to the 13317 ** number of phrases in the current query, as returned by xPhraseCount, 13318 ** 0 is returned. Otherwise, this function returns the number of tokens in 13319 ** phrase iPhrase of the query. Phrases are numbered starting from zero. 13320 ** 13321 ** xInstCount: 13322 ** Set *pnInst to the total number of occurrences of all phrases within 13323 ** the query within the current row. Return SQLITE_OK if successful, or 13324 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 13325 ** 13326 ** This API can be quite slow if used with an FTS5 table created with the 13327 ** "detail=none" or "detail=column" option. If the FTS5 table is created 13328 ** with either "detail=none" or "detail=column" and "content=" option 13329 ** (i.e. if it is a contentless table), then this API always returns 0. 13330 ** 13331 ** xInst: 13332 ** Query for the details of phrase match iIdx within the current row. 13333 ** Phrase matches are numbered starting from zero, so the iIdx argument 13334 ** should be greater than or equal to zero and smaller than the value 13335 ** output by xInstCount(). If iIdx is less than zero or greater than 13336 ** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned. 13337 ** 13338 ** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol 13339 ** to the column in which it occurs and *piOff the token offset of the 13340 ** first token of the phrase. SQLITE_OK is returned if successful, or an 13341 ** error code (i.e. SQLITE_NOMEM) if an error occurs. 13342 ** 13343 ** This API can be quite slow if used with an FTS5 table created with the 13344 ** "detail=none" or "detail=column" option. 13345 ** 13346 ** xRowid: 13347 ** Returns the rowid of the current row. 13348 ** 13349 ** xTokenize: 13350 ** Tokenize text using the tokenizer belonging to the FTS5 table. 13351 ** 13352 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 13353 ** This API function is used to query the FTS table for phrase iPhrase 13354 ** of the current query. Specifically, a query equivalent to: 13355 ** 13356 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 13357 ** 13358 ** with $p set to a phrase equivalent to the phrase iPhrase of the 13359 ** current query is executed. Any column filter that applies to 13360 ** phrase iPhrase of the current query is included in $p. For each 13361 ** row visited, the callback function passed as the fourth argument 13362 ** is invoked. The context and API objects passed to the callback 13363 ** function may be used to access the properties of each matched row. 13364 ** Invoking Api.xUserData() returns a copy of the pointer passed as 13365 ** the third argument to pUserData. 13366 ** 13367 ** If parameter iPhrase is less than zero, or greater than or equal to 13368 ** the number of phrases in the query, as returned by xPhraseCount(), 13369 ** this function returns SQLITE_RANGE. 13370 ** 13371 ** If the callback function returns any value other than SQLITE_OK, the 13372 ** query is abandoned and the xQueryPhrase function returns immediately. 13373 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 13374 ** Otherwise, the error code is propagated upwards. 13375 ** 13376 ** If the query runs to completion without incident, SQLITE_OK is returned. 13377 ** Or, if some error occurs before the query completes or is aborted by 13378 ** the callback, an SQLite error code is returned. 13379 ** 13380 ** 13381 ** xSetAuxdata(pFts5, pAux, xDelete) 13382 ** 13383 ** Save the pointer passed as the second argument as the extension function's 13384 ** "auxiliary data". The pointer may then be retrieved by the current or any 13385 ** future invocation of the same fts5 extension function made as part of 13386 ** the same MATCH query using the xGetAuxdata() API. 13387 ** 13388 ** Each extension function is allocated a single auxiliary data slot for 13389 ** each FTS query (MATCH expression). If the extension function is invoked 13390 ** more than once for a single FTS query, then all invocations share a 13391 ** single auxiliary data context. 13392 ** 13393 ** If there is already an auxiliary data pointer when this function is 13394 ** invoked, then it is replaced by the new pointer. If an xDelete callback 13395 ** was specified along with the original pointer, it is invoked at this 13396 ** point. 13397 ** 13398 ** The xDelete callback, if one is specified, is also invoked on the 13399 ** auxiliary data pointer after the FTS5 query has finished. 13400 ** 13401 ** If an error (e.g. an OOM condition) occurs within this function, 13402 ** the auxiliary data is set to NULL and an error code returned. If the 13403 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 13404 ** pointer before returning. 13405 ** 13406 ** 13407 ** xGetAuxdata(pFts5, bClear) 13408 ** 13409 ** Returns the current auxiliary data pointer for the fts5 extension 13410 ** function. See the xSetAuxdata() method for details. 13411 ** 13412 ** If the bClear argument is non-zero, then the auxiliary data is cleared 13413 ** (set to NULL) before this function returns. In this case the xDelete, 13414 ** if any, is not invoked. 13415 ** 13416 ** 13417 ** xRowCount(pFts5, pnRow) 13418 ** 13419 ** This function is used to retrieve the total number of rows in the table. 13420 ** In other words, the same value that would be returned by: 13421 ** 13422 ** SELECT count(*) FROM ftstable; 13423 ** 13424 ** xPhraseFirst() 13425 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 13426 ** method, to iterate through all instances of a single query phrase within 13427 ** the current row. This is the same information as is accessible via the 13428 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 13429 ** to use, this API may be faster under some circumstances. To iterate 13430 ** through instances of phrase iPhrase, use the following code: 13431 ** 13432 ** Fts5PhraseIter iter; 13433 ** int iCol, iOff; 13434 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 13435 ** iCol>=0; 13436 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 13437 ** ){ 13438 ** // An instance of phrase iPhrase at offset iOff of column iCol 13439 ** } 13440 ** 13441 ** The Fts5PhraseIter structure is defined above. Applications should not 13442 ** modify this structure directly - it should only be used as shown above 13443 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 13444 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 13445 ** 13446 ** This API can be quite slow if used with an FTS5 table created with the 13447 ** "detail=none" or "detail=column" option. If the FTS5 table is created 13448 ** with either "detail=none" or "detail=column" and "content=" option 13449 ** (i.e. if it is a contentless table), then this API always iterates 13450 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 13451 ** 13452 ** In all cases, matches are visited in (column ASC, offset ASC) order. 13453 ** i.e. all those in column 0, sorted by offset, followed by those in 13454 ** column 1, etc. 13455 ** 13456 ** xPhraseNext() 13457 ** See xPhraseFirst above. 13458 ** 13459 ** xPhraseFirstColumn() 13460 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 13461 ** and xPhraseNext() APIs described above. The difference is that instead 13462 ** of iterating through all instances of a phrase in the current row, these 13463 ** APIs are used to iterate through the set of columns in the current row 13464 ** that contain one or more instances of a specified phrase. For example: 13465 ** 13466 ** Fts5PhraseIter iter; 13467 ** int iCol; 13468 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 13469 ** iCol>=0; 13470 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 13471 ** ){ 13472 ** // Column iCol contains at least one instance of phrase iPhrase 13473 ** } 13474 ** 13475 ** This API can be quite slow if used with an FTS5 table created with the 13476 ** "detail=none" option. If the FTS5 table is created with either 13477 ** "detail=none" "content=" option (i.e. if it is a contentless table), 13478 ** then this API always iterates through an empty set (all calls to 13479 ** xPhraseFirstColumn() set iCol to -1). 13480 ** 13481 ** The information accessed using this API and its companion 13482 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 13483 ** (or xInst/xInstCount). The chief advantage of this API is that it is 13484 ** significantly more efficient than those alternatives when used with 13485 ** "detail=column" tables. 13486 ** 13487 ** xPhraseNextColumn() 13488 ** See xPhraseFirstColumn above. 13489 ** 13490 ** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken) 13491 ** This is used to access token iToken of phrase iPhrase of the current 13492 ** query. Before returning, output parameter *ppToken is set to point 13493 ** to a buffer containing the requested token, and *pnToken to the 13494 ** size of this buffer in bytes. 13495 ** 13496 ** If iPhrase or iToken are less than zero, or if iPhrase is greater than 13497 ** or equal to the number of phrases in the query as reported by 13498 ** xPhraseCount(), or if iToken is equal to or greater than the number of 13499 ** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken 13500 are both zeroed. 13501 ** 13502 ** The output text is not a copy of the query text that specified the 13503 ** token. It is the output of the tokenizer module. For tokendata=1 13504 ** tables, this includes any embedded 0x00 and trailing data. 13505 ** 13506 ** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken) 13507 ** This is used to access token iToken of phrase hit iIdx within the 13508 ** current row. If iIdx is less than zero or greater than or equal to the 13509 ** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise, 13510 ** output variable (*ppToken) is set to point to a buffer containing the 13511 ** matching document token, and (*pnToken) to the size of that buffer in 13512 ** bytes. 13513 ** 13514 ** The output text is not a copy of the document text that was tokenized. 13515 ** It is the output of the tokenizer module. For tokendata=1 tables, this 13516 ** includes any embedded 0x00 and trailing data. 13517 ** 13518 ** This API may be slow in some cases if the token identified by parameters 13519 ** iIdx and iToken matched a prefix token in the query. In most cases, the 13520 ** first call to this API for each prefix token in the query is forced 13521 ** to scan the portion of the full-text index that matches the prefix 13522 ** token to collect the extra data required by this API. If the prefix 13523 ** token matches a large number of token instances in the document set, 13524 ** this may be a performance problem. 13525 ** 13526 ** If the user knows in advance that a query may use this API for a 13527 ** prefix token, FTS5 may be configured to collect all required data as part 13528 ** of the initial querying of the full-text index, avoiding the second scan 13529 ** entirely. This also causes prefix queries that do not use this API to 13530 ** run more slowly and use more memory. FTS5 may be configured in this way 13531 ** either on a per-table basis using the [FTS5 insttoken | 'insttoken'] 13532 ** option, or on a per-query basis using the 13533 ** [fts5_insttoken | fts5_insttoken()] user function. 13534 ** 13535 ** This API can be quite slow if used with an FTS5 table created with the 13536 ** "detail=none" or "detail=column" option. 13537 ** 13538 ** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale) 13539 ** If parameter iCol is less than zero, or greater than or equal to the 13540 ** number of columns in the table, SQLITE_RANGE is returned. 13541 ** 13542 ** Otherwise, this function attempts to retrieve the locale associated 13543 ** with column iCol of the current row. Usually, there is no associated 13544 ** locale, and output parameters (*pzLocale) and (*pnLocale) are set 13545 ** to NULL and 0, respectively. However, if the fts5_locale() function 13546 ** was used to associate a locale with the value when it was inserted 13547 ** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated 13548 ** buffer containing the name of the locale in utf-8 encoding. (*pnLocale) 13549 ** is set to the size in bytes of the buffer, not including the 13550 ** nul-terminator. 13551 ** 13552 ** If successful, SQLITE_OK is returned. Or, if an error occurs, an 13553 ** SQLite error code is returned. The final value of the output parameters 13554 ** is undefined in this case. 13555 ** 13556 ** xTokenize_v2: 13557 ** Tokenize text using the tokenizer belonging to the FTS5 table. This 13558 ** API is the same as the xTokenize() API, except that it allows a tokenizer 13559 ** locale to be specified. 13560 */ 13561 struct Fts5ExtensionApi { 13562 int iVersion; /* Currently always set to 4 */ 13563 13564 void *(*xUserData)(Fts5Context*); 13565 13566 int (*xColumnCount)(Fts5Context*); 13567 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 13568 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 13569 13570 int (*xTokenize)(Fts5Context*, 13571 const char *pText, int nText, /* Text to tokenize */ 13572 void *pCtx, /* Context passed to xToken() */ 13573 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 13574 ); 13575 13576 int (*xPhraseCount)(Fts5Context*); 13577 int (*xPhraseSize)(Fts5Context*, int iPhrase); 13578 13579 int (*xInstCount)(Fts5Context*, int *pnInst); 13580 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 13581 13582 sqlite3_int64 (*xRowid)(Fts5Context*); 13583 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 13584 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 13585 13586 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 13587 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 13588 ); 13589 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 13590 void *(*xGetAuxdata)(Fts5Context*, int bClear); 13591 13592 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 13593 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 13594 13595 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 13596 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 13597 13598 /* Below this point are iVersion>=3 only */ 13599 int (*xQueryToken)(Fts5Context*, 13600 int iPhrase, int iToken, 13601 const char **ppToken, int *pnToken 13602 ); 13603 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*); 13604 13605 /* Below this point are iVersion>=4 only */ 13606 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn); 13607 int (*xTokenize_v2)(Fts5Context*, 13608 const char *pText, int nText, /* Text to tokenize */ 13609 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */ 13610 void *pCtx, /* Context passed to xToken() */ 13611 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 13612 ); 13613 }; 13614 13615 /* 13616 ** CUSTOM AUXILIARY FUNCTIONS 13617 *************************************************************************/ 13618 13619 /************************************************************************* 13620 ** CUSTOM TOKENIZERS 13621 ** 13622 ** Applications may also register custom tokenizer types. A tokenizer 13623 ** is registered by providing fts5 with a populated instance of the 13624 ** following structure. All structure methods must be defined, setting 13625 ** any member of the fts5_tokenizer struct to NULL leads to undefined 13626 ** behaviour. The structure methods are expected to function as follows: 13627 ** 13628 ** xCreate: 13629 ** This function is used to allocate and initialize a tokenizer instance. 13630 ** A tokenizer instance is required to actually tokenize text. 13631 ** 13632 ** The first argument passed to this function is a copy of the (void*) 13633 ** pointer provided by the application when the fts5_tokenizer_v2 object 13634 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 13635 ** The second and third arguments are an array of nul-terminated strings 13636 ** containing the tokenizer arguments, if any, specified following the 13637 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 13638 ** to create the FTS5 table. 13639 ** 13640 ** The final argument is an output variable. If successful, (*ppOut) 13641 ** should be set to point to the new tokenizer handle and SQLITE_OK 13642 ** returned. If an error occurs, some value other than SQLITE_OK should 13643 ** be returned. In this case, fts5 assumes that the final value of *ppOut 13644 ** is undefined. 13645 ** 13646 ** xDelete: 13647 ** This function is invoked to delete a tokenizer handle previously 13648 ** allocated using xCreate(). Fts5 guarantees that this function will 13649 ** be invoked exactly once for each successful call to xCreate(). 13650 ** 13651 ** xTokenize: 13652 ** This function is expected to tokenize the nText byte string indicated 13653 ** by argument pText. pText may or may not be nul-terminated. The first 13654 ** argument passed to this function is a pointer to an Fts5Tokenizer object 13655 ** returned by an earlier call to xCreate(). 13656 ** 13657 ** The third argument indicates the reason that FTS5 is requesting 13658 ** tokenization of the supplied text. This is always one of the following 13659 ** four values: 13660 ** 13661 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 13662 ** or removed from the FTS table. The tokenizer is being invoked to 13663 ** determine the set of tokens to add to (or delete from) the 13664 ** FTS index. 13665 ** 13666 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 13667 ** against the FTS index. The tokenizer is being called to tokenize 13668 ** a bareword or quoted string specified as part of the query. 13669 ** 13670 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 13671 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 13672 ** followed by a "*" character, indicating that the last token 13673 ** returned by the tokenizer will be treated as a token prefix. 13674 ** 13675 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 13676 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 13677 ** function. Or an fts5_api.xColumnSize() request made by the same 13678 ** on a columnsize=0 database. 13679 ** </ul> 13680 ** 13681 ** The sixth and seventh arguments passed to xTokenize() - pLocale and 13682 ** nLocale - are a pointer to a buffer containing the locale to use for 13683 ** tokenization (e.g. "en_US") and its size in bytes, respectively. The 13684 ** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in 13685 ** which case nLocale is always 0) to indicate that the tokenizer should 13686 ** use its default locale. 13687 ** 13688 ** For each token in the input string, the supplied callback xToken() must 13689 ** be invoked. The first argument to it should be a copy of the pointer 13690 ** passed as the second argument to xTokenize(). The third and fourth 13691 ** arguments are a pointer to a buffer containing the token text, and the 13692 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 13693 ** of the first byte of and first byte immediately following the text from 13694 ** which the token is derived within the input. 13695 ** 13696 ** The second argument passed to the xToken() callback ("tflags") should 13697 ** normally be set to 0. The exception is if the tokenizer supports 13698 ** synonyms. In this case see the discussion below for details. 13699 ** 13700 ** FTS5 assumes the xToken() callback is invoked for each token in the 13701 ** order that they occur within the input text. 13702 ** 13703 ** If an xToken() callback returns any value other than SQLITE_OK, then 13704 ** the tokenization should be abandoned and the xTokenize() method should 13705 ** immediately return a copy of the xToken() return value. Or, if the 13706 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 13707 ** if an error occurs with the xTokenize() implementation itself, it 13708 ** may abandon the tokenization and return any error code other than 13709 ** SQLITE_OK or SQLITE_DONE. 13710 ** 13711 ** If the tokenizer is registered using an fts5_tokenizer_v2 object, 13712 ** then the xTokenize() method has two additional arguments - pLocale 13713 ** and nLocale. These specify the locale that the tokenizer should use 13714 ** for the current request. If pLocale and nLocale are both 0, then the 13715 ** tokenizer should use its default locale. Otherwise, pLocale points to 13716 ** an nLocale byte buffer containing the name of the locale to use as utf-8 13717 ** text. pLocale is not nul-terminated. 13718 ** 13719 ** FTS5_TOKENIZER 13720 ** 13721 ** There is also an fts5_tokenizer object. This is an older, deprecated, 13722 ** version of fts5_tokenizer_v2. It is similar except that: 13723 ** 13724 ** <ul> 13725 ** <li> There is no "iVersion" field, and 13726 ** <li> The xTokenize() method does not take a locale argument. 13727 ** </ul> 13728 ** 13729 ** Legacy fts5_tokenizer tokenizers must be registered using the 13730 ** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2(). 13731 ** 13732 ** Tokenizer implementations registered using either API may be retrieved 13733 ** using both xFindTokenizer() and xFindTokenizer_v2(). 13734 ** 13735 ** SYNONYM SUPPORT 13736 ** 13737 ** Custom tokenizers may also support synonyms. Consider a case in which a 13738 ** user wishes to query for a phrase such as "first place". Using the 13739 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 13740 ** of "first place" within the document set, but not alternative forms 13741 ** such as "1st place". In some applications, it would be better to match 13742 ** all instances of "first place" or "1st place" regardless of which form 13743 ** the user specified in the MATCH query text. 13744 ** 13745 ** There are several ways to approach this in FTS5: 13746 ** 13747 ** <ol><li> By mapping all synonyms to a single token. In this case, using 13748 ** the above example, this means that the tokenizer returns the 13749 ** same token for inputs "first" and "1st". Say that token is in 13750 ** fact "first", so that when the user inserts the document "I won 13751 ** 1st place" entries are added to the index for tokens "i", "won", 13752 ** "first" and "place". If the user then queries for '1st + place', 13753 ** the tokenizer substitutes "first" for "1st" and the query works 13754 ** as expected. 13755 ** 13756 ** <li> By querying the index for all synonyms of each query term 13757 ** separately. In this case, when tokenizing query text, the 13758 ** tokenizer may provide multiple synonyms for a single term 13759 ** within the document. FTS5 then queries the index for each 13760 ** synonym individually. For example, faced with the query: 13761 ** 13762 ** <codeblock> 13763 ** ... MATCH 'first place'</codeblock> 13764 ** 13765 ** the tokenizer offers both "1st" and "first" as synonyms for the 13766 ** first token in the MATCH query and FTS5 effectively runs a query 13767 ** similar to: 13768 ** 13769 ** <codeblock> 13770 ** ... MATCH '(first OR 1st) place'</codeblock> 13771 ** 13772 ** except that, for the purposes of auxiliary functions, the query 13773 ** still appears to contain just two phrases - "(first OR 1st)" 13774 ** being treated as a single phrase. 13775 ** 13776 ** <li> By adding multiple synonyms for a single term to the FTS index. 13777 ** Using this method, when tokenizing document text, the tokenizer 13778 ** provides multiple synonyms for each token. So that when a 13779 ** document such as "I won first place" is tokenized, entries are 13780 ** added to the FTS index for "i", "won", "first", "1st" and 13781 ** "place". 13782 ** 13783 ** This way, even if the tokenizer does not provide synonyms 13784 ** when tokenizing query text (it should not - to do so would be 13785 ** inefficient), it doesn't matter if the user queries for 13786 ** 'first + place' or '1st + place', as there are entries in the 13787 ** FTS index corresponding to both forms of the first token. 13788 ** </ol> 13789 ** 13790 ** Whether it is parsing document or query text, any call to xToken that 13791 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 13792 ** is considered to supply a synonym for the previous token. For example, 13793 ** when parsing the document "I won first place", a tokenizer that supports 13794 ** synonyms would call xToken() 5 times, as follows: 13795 ** 13796 ** <codeblock> 13797 ** xToken(pCtx, 0, "i", 1, 0, 1); 13798 ** xToken(pCtx, 0, "won", 3, 2, 5); 13799 ** xToken(pCtx, 0, "first", 5, 6, 11); 13800 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 13801 ** xToken(pCtx, 0, "place", 5, 12, 17); 13802 **</codeblock> 13803 ** 13804 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 13805 ** xToken() is called. Multiple synonyms may be specified for a single token 13806 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 13807 ** There is no limit to the number of synonyms that may be provided for a 13808 ** single token. 13809 ** 13810 ** In many cases, method (1) above is the best approach. It does not add 13811 ** extra data to the FTS index or require FTS5 to query for multiple terms, 13812 ** so it is efficient in terms of disk space and query speed. However, it 13813 ** does not support prefix queries very well. If, as suggested above, the 13814 ** token "first" is substituted for "1st" by the tokenizer, then the query: 13815 ** 13816 ** <codeblock> 13817 ** ... MATCH '1s*'</codeblock> 13818 ** 13819 ** will not match documents that contain the token "1st" (as the tokenizer 13820 ** will probably not map "1s" to any prefix of "first"). 13821 ** 13822 ** For full prefix support, method (3) may be preferred. In this case, 13823 ** because the index contains entries for both "first" and "1st", prefix 13824 ** queries such as 'fi*' or '1s*' will match correctly. However, because 13825 ** extra entries are added to the FTS index, this method uses more space 13826 ** within the database. 13827 ** 13828 ** Method (2) offers a midpoint between (1) and (3). Using this method, 13829 ** a query such as '1s*' will match documents that contain the literal 13830 ** token "1st", but not "first" (assuming the tokenizer is not able to 13831 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 13832 ** will match against "1st" and "first". This method does not require 13833 ** extra disk space, as no extra entries are added to the FTS index. 13834 ** On the other hand, it may require more CPU cycles to run MATCH queries, 13835 ** as separate queries of the FTS index are required for each synonym. 13836 ** 13837 ** When using methods (2) or (3), it is important that the tokenizer only 13838 ** provide synonyms when tokenizing document text (method (3)) or query 13839 ** text (method (2)), not both. Doing so will not cause any errors, but is 13840 ** inefficient. 13841 */ 13842 typedef struct Fts5Tokenizer Fts5Tokenizer; 13843 typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2; 13844 struct fts5_tokenizer_v2 { 13845 int iVersion; /* Currently always 2 */ 13846 13847 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 13848 void (*xDelete)(Fts5Tokenizer*); 13849 int (*xTokenize)(Fts5Tokenizer*, 13850 void *pCtx, 13851 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 13852 const char *pText, int nText, 13853 const char *pLocale, int nLocale, 13854 int (*xToken)( 13855 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 13856 int tflags, /* Mask of FTS5_TOKEN_* flags */ 13857 const char *pToken, /* Pointer to buffer containing token */ 13858 int nToken, /* Size of token in bytes */ 13859 int iStart, /* Byte offset of token within input text */ 13860 int iEnd /* Byte offset of end of token within input text */ 13861 ) 13862 ); 13863 }; 13864 13865 /* 13866 ** New code should use the fts5_tokenizer_v2 type to define tokenizer 13867 ** implementations. The following type is included for legacy applications 13868 ** that still use it. 13869 */ 13870 typedef struct fts5_tokenizer fts5_tokenizer; 13871 struct fts5_tokenizer { 13872 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 13873 void (*xDelete)(Fts5Tokenizer*); 13874 int (*xTokenize)(Fts5Tokenizer*, 13875 void *pCtx, 13876 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 13877 const char *pText, int nText, 13878 int (*xToken)( 13879 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 13880 int tflags, /* Mask of FTS5_TOKEN_* flags */ 13881 const char *pToken, /* Pointer to buffer containing token */ 13882 int nToken, /* Size of token in bytes */ 13883 int iStart, /* Byte offset of token within input text */ 13884 int iEnd /* Byte offset of end of token within input text */ 13885 ) 13886 ); 13887 }; 13888 13889 13890 /* Flags that may be passed as the third argument to xTokenize() */ 13891 #define FTS5_TOKENIZE_QUERY 0x0001 13892 #define FTS5_TOKENIZE_PREFIX 0x0002 13893 #define FTS5_TOKENIZE_DOCUMENT 0x0004 13894 #define FTS5_TOKENIZE_AUX 0x0008 13895 13896 /* Flags that may be passed by the tokenizer implementation back to FTS5 13897 ** as the third argument to the supplied xToken callback. */ 13898 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 13899 13900 /* 13901 ** END OF CUSTOM TOKENIZERS 13902 *************************************************************************/ 13903 13904 /************************************************************************* 13905 ** FTS5 EXTENSION REGISTRATION API 13906 */ 13907 typedef struct fts5_api fts5_api; 13908 struct fts5_api { 13909 int iVersion; /* Currently always set to 3 */ 13910 13911 /* Create a new tokenizer */ 13912 int (*xCreateTokenizer)( 13913 fts5_api *pApi, 13914 const char *zName, 13915 void *pUserData, 13916 fts5_tokenizer *pTokenizer, 13917 void (*xDestroy)(void*) 13918 ); 13919 13920 /* Find an existing tokenizer */ 13921 int (*xFindTokenizer)( 13922 fts5_api *pApi, 13923 const char *zName, 13924 void **ppUserData, 13925 fts5_tokenizer *pTokenizer 13926 ); 13927 13928 /* Create a new auxiliary function */ 13929 int (*xCreateFunction)( 13930 fts5_api *pApi, 13931 const char *zName, 13932 void *pUserData, 13933 fts5_extension_function xFunction, 13934 void (*xDestroy)(void*) 13935 ); 13936 13937 /* APIs below this point are only available if iVersion>=3 */ 13938 13939 /* Create a new tokenizer */ 13940 int (*xCreateTokenizer_v2)( 13941 fts5_api *pApi, 13942 const char *zName, 13943 void *pUserData, 13944 fts5_tokenizer_v2 *pTokenizer, 13945 void (*xDestroy)(void*) 13946 ); 13947 13948 /* Find an existing tokenizer */ 13949 int (*xFindTokenizer_v2)( 13950 fts5_api *pApi, 13951 const char *zName, 13952 void **ppUserData, 13953 fts5_tokenizer_v2 **ppTokenizer 13954 ); 13955 }; 13956 13957 /* 13958 ** END OF REGISTRATION API 13959 *************************************************************************/ 13960 13961 #ifdef __cplusplus 13962 } /* end of the 'extern "C"' block */ 13963 #endif 13964 13965 #endif /* _FTS5_H */ 13966 13967 /******** End of fts5.h *********/ 13968 #endif /* SQLITE3_H */