XSD中各个元素的唯一价值 [英] Unique value across elements in XSD

问题描述

我试图在多个complexType元素中使用的元素上强制使用唯一值.

I'm trying to enforce a unique value across an element used in multiple complexType elements.

例如:

<xs:element name="lmt">
    <xs:complexType>
        <xs:choice maxOccurs="unbounded">
            <xs:element ref="lf" maxOccurs="unbounded"/>
            <xs:element ref="cdl" maxOccurs="unbounded"/>
        </xs:choice>
    </xs:complexType>
    <xs:unique name="uniquePos">
        <xs:selector xpath="./*/pos"/>
        <xs:field xpath="."/>
    </xs:unique>
</xs:element>

<xs:element name="pos">
    <xs:simpleType>
        <xs:restriction base="xs:integer">
            <xs:pattern value="\d{1}"/>
        </xs:restriction>
    </xs:simpleType>
</xs:element>

<xs:element name="lf">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref="pos"/>
            ... more elements ... 
        </xs:sequence>
    </xs:complexType>
</xs:element>

<xs:element name="cdl">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref="pos"/>
            ... more elements ... 
        </xs:sequence>
    </xs:complexType>
</xs:element>

如果我有类似的东西，我希望这样会失败:

I'd like this to fail if I have something like :

<lmt>
    <lf>
        <pos>1</pos>
        ... more elements ... 
    </lf>
    <cdl>
        <pos>1</pos>
        ... more elements ... 
    </cdl>
</lmt>

但是验证

<lmt>
    <lf>
        <pos>1</pos>
        ... more elements ... 
    </lf>
    <cdl>
        <pos>2</pos>
        ... more elements ... 
    </cdl>
</lmt>

目前两者似乎都可以验证.我已经为选择器尝试了./*/pos和.//pos，但是都导致第一个示例无法通过验证.

currently both seem to validate. I've tried both ./*/pos and .//pos for the selector, but either cause the first example to fail validation.

推荐答案

如果希望元素A中的每个B都具有C的唯一值，则应在元素A上定义唯一性约束，则selector表达式应从A中选择B，然后field表达式应从B中选择C.

If you want every B within an element A to have a unique value for C then your uniqueness constraint should be defined on element A, the selector expression should select B from A, and the field expression should select C from B.

因此，在您的情况下，应在未显示给我们的容器元素上定义约束，该容器元素具有lf和cdl作为其子元素.选择应为.//pos或./*/pos，然后该字段应为.

So in your case the constraint should be defined on the container element that you haven't shown us, which has lf and cdl as its children. The selection should be .//pos or perhaps ./*/pos, and the field should then be .

这篇关于XSD中各个元素的唯一价值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！