<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
<xs:simpleType name="money">
<xs:restriction base="xs:decimal">
<xs:fractionDigits value="2"/>
</xs:restriction>
</xs:simpleType>
<xs:element name="catalog">
<xs:complexType>
<xs:sequence>
<xs:element ref="cd" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:key name="uniqueId">
<xs:selector xpath="cd"/>
<xs:field xpath="@id"/>
</xs:key>
</xs:element>
<xs:element name="cd">
<xs:complexType>
<xs:sequence>
<xs:element name="title" type="xs:string"/>
<xs:element name="artist" type="xs:string"/>
<xs:element name="country" type="xs:string"/>
<xs:element name="company" type="xs:string"/>
<xs:element name="price" type="money"/>
<xs:element name="year" type="xs:int"/>
</xs:sequence>
<xs:attribute name="id" type="xs:int" use="required"/>
</xs:complexType>
</xs:element>
</xs:schema>