Parsing xml file with xpath and xquery using eXist-db

Question

I need to fetch the <TITLE> element from the following XML using XQuery (I'm using eXist-db).

<?xml-stylesheet href="shakes.xsl" type="text/xsl"?>
<!--!DOCTYPE PLAY PUBLIC "-//PLAY//EN" "play.dtd"-->
<ClinicalDocument xmlns="urn:hl7-org:v3">
    <PLAY>
        <TITLE>The Tragedy of Hamlet, Prince of Denmark</TITLE>
    </PLAY>
</ClinicalDocument >

When I try with the XQuery below I am not getting the expected output.

xquery version "3.0";

doc("/db/apps/demo/data/hamlet.xml")/ClinicalDocument/PLAY/TITLE

I think the problem is related to the xmlns attribute present in the <ClinicalDocument> tag:

<ClinicalDocument xmlns="urn:hl7-org:v3">

How can I modify my XQuery to retrieve the desired XML element?

score 1 · Accepted Answer · answered Feb 08 '16 at 06:28

1

Declare a prefix that mapped to your XML default namespace, and use that prefix to reference elements in the namespace, something like this :

declare namespace d = "urn:hl7-org:v3";
doc("/db/apps/demo/data/hamlet.xml")/d:ClinicalDocument/d:PLAY/d:TITLE

tested here : http://www.xpathtester.com/xquery/a88f300bbeacdbd846d7aec887d48a0b

answered Feb 08 '16 at 06:28

har07

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actually the tag contain multiple attributes like this, – Arun M R Nair Feb 08 '16 at 06:41
That's not significant as long as your XPath expression doesn't include elements prefixed with those other namespace prefixes – har07 Feb 08 '16 at 06:47
ok. now this is my result,Continuity of Care Document how can i get exact value,by avoiding the title tag also? – Arun M R Nair Feb 08 '16 at 07:03
add `/text()` at the end, or `/string(.)` – har07 Feb 08 '16 at 07:04
Thank you .one more to ask, what if we don;t know the namespace value, or if we need to fetch from different namespace.? – Arun M R Nair Feb 08 '16 at 07:09
Not sure, maybe using `namespace-uri(/*)` to query namespace URI of the root element.. – har07 Feb 08 '16 at 07:17
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/102953/discussion-between-arun-m-r-nair-and-har07). – Arun M R Nair Feb 09 '16 at 06:01

score 1 · Answer 2 · answered Feb 08 '16 at 12:27

For any namespace, you can use the * wildcard in place of the namespace prefix.

So if you just want the text of the title, you can do:

doc("/db/apps/demo/data/hamlet.xml")/*:ClinicalDocument/*:PLAY/*:TITLE/text()

There is no longer the need to define the namespace. (Although you'll find that having a defined schema with a namespace makes working with XQuery much nicer in the long run.)

Parsing xml file with xpath and xquery using eXist-db

2 Answers2