Xpath for getting unique values of node names

问题

I have the following XML:

<MyFruits>
   <Apple>A</Apple>
   <Apple>19</Apple>
   <Mango>12</Mango>
   <Apple>19</Apple>
   <Orange>A</Orange>
   <Orange>A</Orange>
   <Orange>A</Orange>
   <Apple>B</Apple>
   <Apple>19</Apple>
   <Mango>12</Mango>
   <Apple>19</Apple>
   <Orange>10</Orange>
   <Apple>19</Apple>
   <Orange>10</Orange>
   <Apple>C</Apple>
   <Apple>19</Apple>
   <Mango>12</Mango>
   <Apple>19</Apple>
   <Orange>10</Orange>
   <Apple>19</Apple>
   <Orange>10</Orange>
</MyFruits>

I want to get only unique fruits among them (Apple,Mango and Orange)

Can anyone suggest an XPath to retrieve using XPath 1.0?

Thanks

回答1:

I don't think this can be done in a single XPath 1.0 expression because it would require two nested levels of predicates with the inner one depending on the value of the outer one, i.e.

/MyFruits/*[not(preceding-sibling::*[name() = name(node-from-outer-predicate)])]

and this isn't possible in XPath 1.0.

It would be trivial in XPath 2.0

distinct-values(/MyFruits/*/name())

来源：https://stackoverflow.com/questions/24779946/xpath-for-getting-unique-values-of-node-names