[xquery-talk] How to invert the hierarchy of an xml?

[Peng Yu]

Hi,

Suppose that I have an xml where each Article has it is own Journals.
But since the Journals may be the same. I'd like to group the articles
by Journals. I'm still learning XQuery. Could anybody show me how to
do the conversion using XQuery?

<Library>
  <Article>
    <Title>title1</Title>
    <Author>author1</Author>
    <Journal>journal1</Journal>
  </Article>
  <Article>
    <Title>title2</Title>
    <Author>author2</Author>
    <Journal>journal1</Journal>
  </Article>
  <Article>
    <Title>title3</Title>
    <Author>author3</Author>
    <Journal>journal2</Journal>
  </Article>
  <Article>
    <Title>title4</Title>
    <Author>author4</Author>
    <Journal>journal2</Journal>
  </Article>
</Library>

=========================I want to get something the following

<Library>
  <Journal title="journal1">
    <Article>
      <Title>title1</Title>
      <Author>author1</Author>
    </Article>
    <Article>
      <Title>title2</Title>
      <Author>author2</Author>
    </Article>
  </Journal>
  <Journal title="journal2">
    <Article>
      <Title>title3</Title>
      <Author>author3</Author>
    </Article>
    <Article>
      <Title>title4</Title>
      <Author>author4</Author>
    </Article>
  </Journal>
</Library>

-- 
Regards,
Peng