XQuery different and unique nodes

0
votes

I have the following XML document (This example is from W3schools.com with modifications):

<bookstore>
    <book>
      <title lang="en">Everyday Italian</title>
      <author>Giada De Laurentiis</author>
      <section>Children</section>
      <section>Recent</section>
      <year>2005</year>
      <price>30.00</price>
    </book>

    <book>
      <title lang="en">Harry Potter</title>
      <author>J K. Rowling</author>
      <section>Children</section>
      <section>Recent</section>
      <year>2005</year>
      <price>29.99</price>
    </book>

    <book>
      <title lang="en">Learning XML 2: The Reckoning</title>
      <author>Erik T. Simpson</author>
      <section>Terror</section>
      <year>2003</year>
      <price>9.95</price>
    </book>

</bookstore>

How can I retrieve the books which SECTION is the ONLY ONE in the entire document and there is no duplicate? I tried the following XQuery (I need an XQuery for this):

for $x in doc("books.xml")/bookstore/book/
where distinct-values($x/section)
return $x

But it seems returns all of them without duplicates and I want to retrieve the last node, because is the only one with that section.

Any idea? Thank you very much for your support and help!

1
xmlxpathxquery
Are you looking for all book elements with only one section child element? What happens if there is a book with several section child element which are all unique across the document, do you want to select it? Also which version of XQuery do you use? – Martin Honnen
You've given sample data (good), but you've omitted the desired result of your query (bad). Please clarify what you are trying to achieve - answering Martin's question should help with this. – Joe Wicentowski
Thanks for the advise, I'll be more specific next time. Fortunately, Martin answered me in a fantastic way. Thank you again! – Joanmacat

1 Answers

2
votes

If you select /bookstore/book[not(section = (preceding-sibling::book/section | following-sibling::book/section))] then you select all book elements which do not have a section equal to any section of other book elements.