复杂元素的两个例子

例1：
Schema文档：
<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="books">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="book" type="book_info" maxOccurs="unbounded"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
    <xs:complexType name="book_info">
        <xs:sequence>
            <xs:element name="name" type="xs:string"/>
            <xs:element name="author" maxOccurs="3">
                <xs:simpleType>
                    <xs:list itemType="author_3"/>
                </xs:simpleType>
            </xs:element>
            <xs:element name="price" type="xs:decimal"/>
        </xs:sequence>
        <xs:attribute name="id" type="xs:integer" use="required"/>
    </xs:complexType>
    <xs:simpleType name="author_3">
        <xs:restriction base="xs:string">
            <xs:enumeration value="张三"/>
            <xs:enumeration value="李四"/>
            <xs:enumeration value="赵五"/>
        </xs:restriction>
    </xs:simpleType>
</xs:schema>

XML文档：
<?xml version="1.0"?>
<books xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="019.xsd">
    <book id="001">
        <name>XML学习天下</name>
        <author>张三</author>
        <author>李四</author>
        <price>88.50</price>
    </book>
    <book id="002">
        <name>XML百例</name>
        <author>赵五</author>
        <author>李四</author>
        <price>68.00</price>
    </book>
</books>
注：书的作者只能是张三、李四和赵五。

例2：
<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="books">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="book" maxOccurs="unbounded" type="book_value"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
    <xs:complexType name="book_value">
        <xs:sequence>
            <xs:element name="name" type="xs:string"/>
            <xs:element name="author" type="author_3" maxOccurs="3"/>
            <xs:element name="price" type="xs:decimal"/>
        </xs:sequence>
        <xs:attribute name="id" type="xs:integer" use="required"/>
    </xs:complexType>
    <xs:simpleType name="author_3">
        <xs:restriction base="xs:string">
            <xs:enumeration value="张三"/>
            <xs:enumeration value="李四"/>
            <xs:enumeration value="赵五"/>
        </xs:restriction>
    </xs:simpleType>
</xs:schema>

XML文档：
<?xml version="1.0"?>
<books xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="018.xsd">
    <book id="001">
        <name>XML学习天下</name>
        <author>张三</author>
        <price>88.50</price>
    </book>
    <book id="002">
        <name>XML百例</name>
        <author>赵五</author>
        <price>68.00</price>
    </book>
</books>
注：书的作者只能是张三、李四、赵五其中的一个。