How to return last node having namespace in it using Xquery

Question

I have this file, which have namespaces in it, I am trying to write a Xquery which will return, the last node having the namespace, but unabe to find the logic to return the namespace node(PS: I am new to Xquery)

XML File -

<XML>
  <SOAPMessage>
    <soapenv:Envelope   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
      <soapenv:Body>
        <postRequestResponse    xmlns="http://company.com">
          <postRequestReturn>
            <OnlineBRE  xmlns="">
              <Proccode>NUM</Proccode>
            </OnlineBRE>
          </postRequestReturn>
        </postRequestResponse>
      </soapenv:Body>
    </soapenv:Envelope>
  </SOAPMessage>
</XML>

I have tried a query to return node with exact string value, but that didn't work.

While asking an XQuery question you need to provide a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example): (1) Input XML. (2) Your logic, and XQuery that tries to implement it. (3) Desired output based on the #1 above. (4) XQuery processor and its conformance with the XQuery standards: 1.0, 3.0, 3.1, or 4.0. — Yitzhak Khabinsky, Jan 06 '23 at 18:24

score 2 · Answer 1 · answered Jan 06 '23 at 18:44

2

You can look for all elements in the document //* and test whether there is a namespace-uri() in a predicate filter, then select the last() element that has a namespace-uri().

let $doc := 
  <XML>
    <bk:BOOK xmlns:bk="urn:example.microsoft.com:BookInfo" xmlns:money="urn:Finance:Money">
      <bk:TITLE>value1</bk:TITLE>
      <ONLINEBRE />
      <bk:PRICE money:currency="US Dollar">22.95</bk:PRICE>
    </bk:BOOK>
  </XML>
return ($doc//*[namespace-uri()])[last()]

answered Jan 06 '23 at 18:44

Mads Hansen

63,927
12
112
147

This will return all the elements after the last namespace element, how to get the value of the node that have the last namespace, is it a way in Xquery to get the path of the node with the last namespace @MadsHansen – Adarsh Singh Jan 06 '23 at 19:33
1

I don't understand what you mean. Are you asking for the parent of that element? It's easier if you indicate what you actually want, provide an example from your sample XML. – Mads Hansen Jan 06 '23 at 19:52
I have entered the exact xml for which I needed the help, Mads, in this since the last one to have the namespace is ONLINEBRE, so i want the answer to be only "ONLINEBRE", or the XPATH of the tag – Adarsh Singh Jan 06 '23 at 20:24
1

that element **doesn't** have a namespace. You said you wanted to select the last element that **has a namespace**. So, if you want to select the `ONLINEBRE`, what is the logic? – Mads Hansen Jan 06 '23 at 20:44
I want the value of the tag that has the last namespace, lets say i want the answer to be – Adarsh Singh Jan 06 '23 at 20:50
I have added the new XML – Adarsh Singh Jan 06 '23 at 20:51
`postRequestReturn` is bound to the same namespace as `postRequestResponse`, so it's actually the last element that has a namespace. You are looking for the last element that has `@xmlns:*` ?? That's not a normal attribute, so you can't select it via XPath like you can with "real" attributes. Still trying to understand what you are looking to achieve and why. – Mads Hansen Jan 06 '23 at 22:34
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/250918/discussion-between-adarsh-singh-and-mads-hansen). – Adarsh Singh Jan 07 '23 at 04:51
I dont want the value but the element name, for example in your first comment, I want the answer to be – Adarsh Singh Jan 07 '23 at 09:39

score 1 · Accepted Answer · answered Jan 18 '23 at 23:13

Based on your comments on the Mads Hansen's answer I came up with this:

declare namespace array = "http://www.w3.org/2005/xpath-functions/array";

declare function local:ns-changed ($current as element(), $last-ns, $last-element) {
  $current/element() ! (
    let $child-ns := namespace-uri-from-QName(node-name(.))
    return
      if ( $child-ns = $last-ns )
      then local:ns-changed(., $last-ns, $last-element)
      else local:ns-changed(., $child-ns, .)
  ),
  $last-element
};

let $root :=
<XML>
  <SOAPMessage>
    <soapenv:Envelope   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
      <soapenv:Body>
        <postRequestResponse    xmlns="http://company.com">
          <postRequestReturn>
            <OnlineBRE  xmlns="">
              <Proccode>NUM</Proccode>
            </OnlineBRE>
          </postRequestReturn>
        </postRequestResponse>
      </soapenv:Body>
    </soapenv:Envelope>
  </SOAPMessage>
</XML>

let $initial-ns := namespace-uri-from-QName(node-name($root))
let $wanted := head(local:ns-changed($root, $initial-ns, $root))

return $wanted

I may not be pretty and inefficient and also only tested on your provided input, but it does what you want.

Here you can see it in action https://xqueryfiddle.liberty-development.net/3Nzd8c9/1

Currently it returns the last element where the namespace changed. To return the node-name or the value or something else modify the last line.

How to return last node having namespace in it using Xquery

2 Answers2