本文介绍了XML XSD 架构 - 强制架构中的唯一属性值的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
假设我有一个定义以下 XML 的架构:
Lets say I have a schema that defines the following XML:
<Values>
<Add Key="Key1">Value 1</Add>
<Add Key="Key2">Value 2</Add>
<Add Key="Key3">Value 3</Add>
<Add Key="Key4">Value 4</Add>
</Values>
我希望,在架构级别,能够强制 Key 属性的值是唯一的,即上面的示例有效,但以下示例无效:
I would like, at a schema level, to be able to enforce that the values for the Key attribute are unique, i.e. the example above is valid, but the following example would be invalid:
<Values>
<Add Key="Key1">Value 1</Add>
<Add Key="Key2">Value 2</Add>
<Add Key="Key2">Value 3</Add>
<Add Key="Key3">Value 4</Add>
</Values>
注意有两个 Add
元素的 Key
为 Key2
Notice that there are two Add
elements with a Key
of Key2
这里是简单的架构供参考:
For reference here is the simple schema:
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:element name="Values">
<xs:complexType>
<xs:sequence>
<xs:element name="Add" maxOccurs="unbounded">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="Key" type="xs:token" use="required"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
我的印象是这在模式级别是不可能的,但我全神贯注.
I am under the impression that this is not possible at a schema level, however I am all ears.
推荐答案
@BatteryBackupUnit 有正确的想法,但语法更像是:
@BatteryBackupUnit has the right idea, but the syntax is more like:
<xs:element name="Values">
<xs:complexType>
<xs:sequence>
<xs:element ref="Add" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:unique name="UniqueAddKey">
<xs:selector xpath="Add" />
<xs:field xpath="@Key" />
</xs:unique>
</xs:element>
这篇关于XML XSD 架构 - 强制架构中的唯一属性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!