The International Purchase Order Schema
We begin with the schema — actually two schemas. As you can see, the address.xsd schema is included in the complexContent.xsd schema.
<schema targetNamespace="http://www.example.com/IPO"
xmlns="http://www.w3.org/2001/XMLSchema"
xmlns:ipo="http://www.example.com/IPO">
.
.
.
<!-- include address constructs -->
<include schemaLocation="address.xsd"/>
<element name="purchaseOrder" type="ipo:PurchaseOrderType"/>
<element name="comment" type="string"/>
<complexType name="PurchaseOrderType">
<sequence>
<element name="shipTo" type="ipo:Address"/>
<element name="billTo" type="ipo:Address"/>
<element ref="ipo:comment" minOccurs="0"/>
<element name="items" type="ipo:Items"/>
</sequence>
<attribute name="orderDate" type="date"/>
</complexType>
<complexType name="Items">
<sequence>
<element name="item" minOccurs="0" maxOccurs="unbounded">
<complexType>
<sequence>
<element name="productName" type="string"/>
<element name="quantity">
<simpleType>
<restriction base="positiveInteger">
<maxExclusive value="100"/>
</restriction>
</simpleType>
</element>
<element name="USPrice" type="decimal"/>
<element ref="ipo:comment" minOccurs="0"/>
<element name="shipDate" type="date" minOccurs="0"/>
</sequence>
<attribute name="partNum" type="ipo:SKU" use="required"/>
</complexType>
</element>
</sequence>
</complexType>
<simpleType name="SKU">
<restriction base="string">
<pattern value="\d{3}-[A-Z]{2}"/>
</restriction>
</simpleType>
<complexType name="ConfirmedItems">
<complexContent>
<restriction base="ipo:Items">
<sequence>
<!-- item element is different than in Items -->
<element name="item" minOccurs="1" maxOccurs="unbounded">
<!-- remainder of definition is same as Items -->
<complexType>
<sequence>
<element name="productName" type="string"/>
<element name="quantity">
<simpleType>
<restriction base="positiveInteger">
<maxExclusive value="100"/>
</restriction>
</simpleType>
</element>
<element name="USPrice" type="decimal"/>
<element ref="ipo:comment" minOccurs="0"/>
<element name="shipDate" type="date" minOccurs="0"/>
</sequence>
<attribute name="partNum" type="ipo:SKU" use="required"/>
</complexType>
</element>
</sequence>
</restriction>
</complexContent>
</complexType>
</schema>
<!--address.xsd -->
<schema targetNamespace="http://www.example.com/IPO"
xmlns="http://www.w3.org/2001/XMLSchema"
xmlns:ipo="http://www.example.com/IPO">
<annotation>
<documentation xml:lang="en">
Addresses for International Purchase order schema
Copyright 2000 Example.com. All rights reserved.
</documentation>
</annotation>
<complexType name="Address">
<sequence>
<element name="name" type="string"/>
<element name="street" type="string"/>
<element name="city" type="string"/>
</sequence>
</complexType>
<complexType name="USAddress">
<complexContent>
<extension base="ipo:Address">
<sequence>
<element name="state" type="string"/>
<element name="zip" type="positiveInteger"/>
</sequence>
</extension>
</complexContent>
</complexType>
<complexType name="UKAddress">
<complexContent>
<extension base="ipo:Address">
<sequence>
<element name="postcode" type="ipo:UKPostcode"/>
</sequence>
<attribute name="exportCode" type="positiveInteger" fixed="1"/>
</extension>
</complexContent>
</complexType>
<!-- other Address derivations for more countries -->
<simpleType name="USState">
<restriction base="string">
<enumeration value="AK"/>
<enumeration value="AL"/>
<enumeration value="AR"/>
<!-- and so on ... -->
</restriction>
</simpleType>
<!-- simple type definition for UKPostcode -->
<simpleType name="UKPostcode">
<restriction base="string">
</restriction>
</simpleType>
</schema>