使用 XPath 1.0 仅选择不同的值

Question

如何使用 XPath 1.0 仅返回 唯一 City 值，其中 Name 的 Name 使用 XPath 1.0？

<StateDataSet>
    <State>
        <Name>Washington</Name>
        <City>Seattle</City>
        <business>Starbucks</business>
    </State>
    <State>
        <Name>Washington</Name>
        <City>Seattle</City>
        <business>Amazon</business>
    </State>
    <State>
        <Name>Washington</Name>
        <City>Redmond</City>
        <business>Microsoft</business>
    </State>
    <State>
        <Name>Washington</Name>
        <City>Redmond</City>
        <business>Starbucks</business>
    </State>
    <State>
        <Name>Washington</Name>
        <City>Seattle</City>
        <business>Dicks</business>
    </State>
    <State>
        <Name>Alaska</Name>
        <City>Anchorage</City>
        <business>Starbucks</business>
    </State>
    <State>
        <Name>Oregon</Name>
        <City>Portland</City>
        <business>Starbucks</business>
    </State>
    <State>
        <Name>Alaska</Name>
        <City>Gnome</City>
        <business>Starbucks</business>
    </State>
</StateDataSet>

到目前为止，我已经尝试了以下 XPath 查询：

/StateDataSet/State[Name ='Washington' and not (State[Name='Washington'] = following-sibling::State[Name='Washington'])]/City

这返回了华盛顿的城市，但值不是唯一的。我使用xpathtester.com 测试了我的查询

我做错了什么？我的查询基于get-distinct-values-within-specific-attributes

Answer 1

这个 XPath，

/StateDataSet/State[Name ='Washington' and 
                    not(City = preceding-sibling::State[Name='Washington']/City)]
             /City

将在State 元素中选择唯一的City 元素和Name = 'Washington'：

<City>Seattle</City>
<City>Redmond</City>

根据要求。