Xml xs:unique我如何让它工作

嘿，我想强制一个属性在我的XML文档中是唯一的。我刚刚开始学习XML。我想让每个人都有一个唯一的id。我已经查看了xs:unique，但不能完全弄清楚它在这里的位置，它不会在每次尝试时都进行解析。 模式如下：

<?xml version='1.0' encoding='utf-8'?>
<xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema'>
    <xs:element name='people' type='peopleType' /><!-- Root Element -->

    <xs:complexType name='peopleType'>
        <xs:sequence>
            <xs:element name='person' type='personType' maxOccurs='unbounded'/>
        </xs:sequence>
    </xs:complexType><!-- End peopleType-->

    <xs:complexType name='personType'>

        <xs:sequence>
            <xs:element name='name' type='nameType' maxOccurs='unbounded' />
            <xs:element name='email' minOccurs='1'>
                <xs:simpleType>
                    <xs:restriction base='xs:string'>
                        <xs:pattern value='([a-zA-Z0-9_-])*([.])?([a-zA-Z0-9_-])*([.])?([a-zA-Z0-9_-])*[@]([a-zA-Z0-9_-])*([.])?([a-zA-Z0-9_-])*([.])?([a-zA-Z0-9_-])*' />
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
            <xs:element name='favColour' type='colourType' minOccurs='0' />

        </xs:sequence>

        <xs:attribute name='id' type='xs:integer' />

    </xs:complexType><!--End personType -->

    <xs:complexType name='nameType'>
        <xs:sequence>
            <xs:element name='given' minOccurs='1'>
                <xs:simpleType>
                    <xs:restriction base='xs:string'>
                        <xs:pattern value='[A-Z]([a-z])*' />
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
            <xs:element name='family' minOccurs='1'>
                <xs:simpleType>
                    <xs:restriction base='xs:string'>
                        <xs:pattern value='[A-Z]([a-z])*' />
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
        </xs:sequence>
    </xs:complexType><!-- End nameType -->

    <xs:complexType name='colourType'>
        <xs:sequence>
            <xs:element name='red' minOccurs='1' >
                <xs:simpleType>
                    <xs:restriction base='xs:integer'>
                        <xs:minInclusive value='0' />
                        <xs:maxInclusive value='255' />
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
            <xs:element name='green' minOccurs='1' >
                <xs:simpleType>
                    <xs:restriction base='xs:integer'>
                        <xs:minInclusive value='0' />
                        <xs:maxInclusive value='255' />
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
            <xs:element name='blue' minOccurs='1'>
                <xs:simpleType>
                    <xs:restriction base='xs:integer'>
                        <xs:minInclusive value='0' />
                        <xs:maxInclusive value='255' />
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
        </xs:sequence>
    </xs:complexType><!-- End colourType -->
</xs:schema>

[编辑]在听取建议后，我做了以下更改。它可以解析，但不强制执行唯一属性

<xs:complexType name='peopleType'>
        <xs:sequence>
            <xs:element name='person'  type='personType' maxOccurs='unbounded'>
                <xs:unique name="MyUserNameUniqueKey">
            <xs:selector xpath="person" />
            <xs:field xpath="@id" />
            </xs:unique>
            </xs:element>
        </xs:sequence>
    </xs:complexType><!-- End peopleType--> 

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在人物元素声明中，使用选择器xpath=“person”，fieldxpath=“@id”添加xs:unique声明。如果不起作用，告诉我们你试过什么