XML/XQuery/count

Count nodes

   <source lang="xml">

File: Data.xml <?xml version="1.0"?> <Books>

<Book>book 1</Book>
<Book>book 2</Book>
<Book>book 3</Book>

</Books>

File: Query.xquery <library count="{count(doc("Data.xml")/Books/Book)}">{

 for $b in doc("Data.xml")/Books/Book
   return <book>{$b/text()}</book>
}</library>

Output: <?xml version="1.0" encoding="UTF-8"?> <library count="3">

  <book>book 1</book>
  <book>book 2</book>
  <book>book 3</book>

</library>

</source>