XML/XSD 问题：如何使名称不同的两个元素始终相互匹配

Question

例如：

<Region>
 <RegionID>r1</RegionID>
 <RegionInfor>A</RegionInfor>
 <Subregion>
  <SubregionID>s1</SubregionID>
  <RegionIDAssociation>r1</RegionIDAssociation>
 </Subregion>
</Region>

问题：我想让 RegionIDAssociation 始终匹配 RegionID，这意味着如果 RegionID 是 r1，则子区域的 RegionIDAssociation 必须填充 r1，如何使用 XML SCHEMA (XSD) 实现？

Answer 1

使用key/keyref:

 <xs:element name="Region">
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="RegionID"/>
        <xs:element ref="RegionInfor"/>
        <xs:element ref="Subregion"/>
      </xs:sequence>
    </xs:complexType>
    <xs:key name="region-id">
      <xs:selector xpath="."></xs:selector>
      <xs:field xpath="RegionID"></xs:field>
    </xs:key>
    <xs:keyref refer="region-id" name="subregion-constraint">
      <xs:selector xpath="Subregion"></xs:selector>
      <xs:field xpath="RegionIDAssociation"></xs:field>
    </xs:keyref>
  </xs:element>

XML/XSD 问题：如何使名称不同的两个元素始终相互匹配

XML/XSD ISSUE : How do I make two elements with different names always match with each other

xml

schema

xsd