1  <?xml version="1.0" encoding="UTF-8" ?> 
 2  <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
 3             targetNamespace="http://www.tempuri.org/MainSchema"
 4             xmlns:tns="http://www.tempuri.org/MainSchema"
 5             xmlns:ns="http://www.tempuri.org/ImportedSchema"
 6             elementFormDefault="qualified" >
 7             
 8    <xs:import namespace="http://www.tempuri.org/ImportedSchema" schemaLocation="./import-455953.xsd" />
 9    
10    <xs:complexType name="MyMainType">
11      <xs:sequence>
12        <xs:element name="MainA">
13          <xs:complexType>
14            <xs:attribute name="MainID" type="xs:int"/>
15          </xs:complexType>
16        </xs:element>
17        <xs:element ref="ns:AnotherElement" />
18      </xs:sequence>
19    </xs:complexType>
20  
21    <xs:element name="MainElement" type="tns:MyMainType">
22      <xs:key name="MainKey" >
23        <xs:selector xpath="tns:MainA" />
24        <xs:field xpath="@MainID" />
25      </xs:key>
26    </xs:element>
27  
28  
29  </xs:schema>