Sample XSD File: Customers and Orders
The following XSD file is used in various examples in the LINQ to XML documentation. This file contains a schema definition for the Sample XML File: Customers and Orders (LINQ to XML). The schema uses the xs:key and xs:keyref features of XSD to establish that the CustomerID attribute of the Customer element is a key, and to establish a relationship between the CustomerID element in each Order element and the CustomerID attribute in each Customer element.
For an example of writing LINQ queries that take advantage of this relationship using the Join clause, see How to: Join Two Collections (C#) (LINQ to XML).
CustomersOrders.xsd
<?xml version="1.0" encoding="utf-8" ?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name='Root'>
<xs:complexType>
<xs:sequence>
<xs:element name='Customers'>
<xs:complexType>
<xs:sequence>
<xs:element name='Customer' type='CustomerType' minOccurs='0' maxOccurs='unbounded' />
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name='Orders'>
<xs:complexType>
<xs:sequence>
<xs:element name='Order' type='OrderType' minOccurs='0' maxOccurs='unbounded' />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
<xs:key name='CustomerIDKey'>
<xs:selector xpath='Customers/Customer'/>
<xs:field xpath='@CustomerID'/>
</xs:key>
<xs:keyref name='CustomerIDKeyRef' refer='CustomerIDKey'>
<xs:selector xpath='Orders/Order'/>
<xs:field xpath='CustomerID'/>
</xs:keyref>
</xs:element>
<xs:complexType name='CustomerType'>
<xs:sequence>
<xs:element name='CompanyName' type='xs:string'/>
<xs:element name='ContactName' type='xs:string'/>
<xs:element name='ContactTitle' type='xs:string'/>
<xs:element name='Phone' type='xs:string'/>
<xs:element name='Fax' minOccurs='0' type='xs:string'/>
<xs:element name='FullAddress' type='AddressType'/>
</xs:sequence>
<xs:attribute name='CustomerID' type='xs:token'/>
</xs:complexType>
<xs:complexType name='AddressType'>
<xs:sequence>
<xs:element name='Address' type='xs:string'/>
<xs:element name='City' type='xs:string'/>
<xs:element name='Region' type='xs:string'/>
<xs:element name='PostalCode' type='xs:string' />
<xs:element name='Country' type='xs:string'/>
</xs:sequence>
<xs:attribute name='CustomerID' type='xs:token'/>
</xs:complexType>
<xs:complexType name='OrderType'>
<xs:sequence>
<xs:element name='CustomerID' type='xs:token'/>
<xs:element name='EmployeeID' type='xs:token'/>
<xs:element name='OrderDate' type='xs:dateTime'/>
<xs:element name='RequiredDate' type='xs:dateTime'/>
<xs:element name='ShipInfo' type='ShipInfoType'/>
</xs:sequence>
</xs:complexType>
<xs:complexType name='ShipInfoType'>
<xs:sequence>
<xs:element name='ShipVia' type='xs:integer'/>
<xs:element name='Freight' type='xs:decimal'/>
<xs:element name='ShipName' type='xs:string'/>
<xs:element name='ShipAddress' type='xs:string'/>
<xs:element name='ShipCity' type='xs:string'/>
<xs:element name='ShipRegion' type='xs:string'/>
<xs:element name='ShipPostalCode' type='xs:string'/>
<xs:element name='ShipCountry' type='xs:string'/>
</xs:sequence>
<xs:attribute name='ShippedDate' type='xs:dateTime'/>
</xs:complexType>
</xs:schema>