Using multiple namespaces in XPATH

Question

There are 2 xml document with different namespaces, e.g.

declare namespace ml1 = "urn:schemas-com:ml1";
declare namespace ml2 = "urn:schemas-com:ml2";

but with same structure. Can I select some nodes using only these namespaces, without *? I mean something like that:

fn:doc($uri)/(ml1 or ml2):root

Updated: Thanks. All suggestions work but not useful for me. Because there can be 3 or more namespaces, and xpath expression will be very large. Any suggestions?

Conclusion: Thanks for the answers. I agree with @MichaelKay that I should process all xml all documents. Problem is solved.

Answer 1

One possible expression is:

  doc($uri)/(ml1:root|ml2:root)

Another is:

  doc($uri)/*[self::ml1:root or self::ml2:root]

In case there can be an unlimited number of prefixes of the form "mlNNNNN"", use:

  doc($uri)/*[matches(substring-before(name(), ':'), '^ml\d+')]

Answer 2

You can use predicates

fn:doc($uri)/*[local-name() = "root" and (namespace-uri() = "urn:schemas-com:ml1" or namespace-uri() = "urn:schemas-com:ml2")]

If your namespace URIs all have a common prefix (as the examples you've supplied suggest) then you can use a construction like

..../*[starts-with(namespace-uri(), "urn:schemas-com:") ...]

If you have a number of namespaces and you can list them all in another XML file:

<namespaces>
  <uri>urn:schemas-com:ml1</uri>
  <uri>urn:schemas-com:ml2</uri>
  <!-- ... -->
</namespaces>

and then the predicate

*[namespace-uri() = fn:doc("namespaces.xml")/namespaces/uri]

would be true if the namespace URI of the node being tested matches any of the namespaces listed in namespaces.xml.