XPath test for node exists and contains a number

Question

I need a condition in XPath or XQuery to determine if a product has the node Id and if that node has a number.

<ns34:Product>
  <ns34:Id>100</ns34:Id>
</ns34:Product>
<ns34:Product>
  <ns34:Id>104</ns34:Id>
</ns34:Product>

Answer 1

Assuming that your actual XML is well-formed with a single root element...

And that you've properly registered a namespace for the ns34 prefix...

And that you've somehow selected the desired Product (no criteria was given in your question) and bound it to variable, $p...

This expression will test whether $p has a ns34:Id child element:

$p/ns34:Id

And this expression will test whether it is a number:

number($p/ns34:Id) = $p/ns34:Id

And this expression will select those products that have an ns34:Id child element that is a number:

//ns34:Product[number(ns34:Id) = ns34:Id]