Question

我对XQuery很新，并且知道这可能是一个简单的答案，但我无法绕过这个问题。

我有一个像这样的XML文件：

<EventLog>
  <SongSet>
    <Song SongID="S002">
      <Title>Band on the Run</Title>
      <Composer>Paul McCartney</Composer>
      <Duration>1.15</Duration>
    </Song>
    <Song SongID="S003">
      <Title>Come on Over</Title>
      <Composer>Shania Twain</Composer>
      <Duration>3.15</Duration>
    </Song>
   </SongSet>
  <ContestantSet>
   <Contestant Name="Randy Stuss" Hometown="Ottawa">
      <Repertoire>
        <SongRef>S002</SongRef>
        <SongRef>S003</SongRef>
      </Repertoire>
     </Contestant>
     <Contestant Name="Fletcher Gee" Hometown="Toronto">
      <Repertoire>
        <SongRef>S002</SongRef>
        <SongRef>S003</SongRef>
      </Repertoire>
    </Contestant>
  </ContestantSet>
</EventLog>

我需要输出看起来像这样：

<songs> 
  <song> 
    <name> SONG NAME1 </name>
    <composer> COMPOSER NAME </composer>
    <singers>
      <singer>Singer1 Name  </singer>  
      <singer>Singer2 Name  </singer>  
    </singers>
  </song>
<songs>

除了将歌手的名字放在一起之外，我可以做所有这些。我的输出如下：

<Songs
  <Song>
    <Title>Band on the Run</Title>
    <Composer>Paul McCartney</Composer>
    <Singers>
      <Singer>Fletcher Gee</Singer>
    </Singers>
  </Song>
  <Song>
    <Title>Band on the Run</Title>
    <Composer>Paul McCartney</Composer>
  <Singers>
    <Singer>Randy Stuss</Singer>
  </Singers>
  </Song>
</Songs>

这是我的XQuery代码：

for $x in //SongSet/Song 
for $y in //ContestantSet/Contestant 
where $x/@SongID = $y/Repertoire/SongRef 
return <Song><Title>{data($x/Title)}</Title>
       <Composer>{data($x/Composer)}</Composer>
       <Singers><Singer>{data($y/@Name)}</Singer></Singers></Song>

我哪里错了？

感谢您的帮助!!!!

Answer 1

一种可能的方式;循环遍历<Song>元素，然后遍历匹配的return <Singers>元素上的<Contestant>部分循环：

for $x in //SongSet/Song 
return <Song><Title>{data($x/Title)}</Title>
       <Composer>{data($x/Composer)}</Composer>
       <Singers>{for $y in //ContestantSet/Contestant[Repertoire/SongRef = $x/@SongID]
                 return <Singer>{data($y/@Name)}</Singer>}</Singers></Song>

<强> Xpathtester Demo

在对相关XML进行测试时，输出符合预期：

<?xml version="1.0" encoding="UTF-8"?>
<Song>
   <Title>Band on the Run</Title>
   <Composer>Paul McCartney</Composer>
   <Singers>
      <Singer>Randy Stuss</Singer>
      <Singer>Fletcher Gee</Singer>
   </Singers>
</Song>
<Song>
   <Title>Come on Over</Title>
   <Composer>Shania Twain</Composer>
   <Singers>
      <Singer>Randy Stuss</Singer>
      <Singer>Fletcher Gee</Singer>
   </Singers>
</Song>

如何让XQuery提取XML文档中的所有匹配节点

1 个答案: