Using XML Query Modules with an XML that has a namespace

Goals and Symptoms

Using the XML document below with an XML Query Module normally you could use this query to find the price of the first HOEP value
/IMODocument/IMODocBody/HOEPs/HOEP[1]/Price

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="http://reports.ieso.ca/docrefs/stylesheet/DispUnconsHOEP_HTML_t1-1.xsl" ?><IMODocument docID="DispUnconsHOEP" xmlns="http://www.theIMO.com/schema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.theIMO.com/schemahttp://reports.ieso.ca/docrefs/schema/DispUnconsHOEP_r1.xsd">
<IMODocHeader>
<DocTitle>Hourly Ontario Energy Price (HOEP) Report</DocTitle>
<DocRevision>1</DocRevision>
<DocConfidentiality>
<DocConfClass>PUB</DocConfClass>
</DocConfidentiality>
<CreatedAt>2010-06-08T08:01:15</CreatedAt>
</IMODocHeader>
<IMODocBody>
<Date>2010-06-08</Date>
<HOEPs>
<HOEP>
<Hour>1</Hour>
<Price>28.81</Price>
<DataSource>DSO-RD</DataSource>
</HOEP>
<HOEP>
<Hour>2</Hour>
<Price>25.52</Price>
<DataSource>DSO-RD</DataSource>
</HOEP>
<HOEP>
<Hour>3</Hour>
<Price>29.09</Price>
<DataSource>DSO-RD</DataSource>
</HOEP>
<HOEP>
<Hour>4</Hour>
<Price>24.92</Price>
<DataSource>DSO-RD</DataSource>
</HOEP>
</HOEPs>
</IMODocBody>
</IMODocument>

Below is a typical xml document

Causes and Fixes

However, some xml documents contain a namespace, that makes it difficult for the XML Import module to define the nodes underneath the namespace.



So a generalized query that ignores namespace can be built like this:

//*[local-name()='HOEPs']/*[local-name()='HOEP'][1]/*[local-name()='Price']



Here is a break down of the query:

//*[local-name()='HOEPs'] = Return all nodes in the document with the name 'HOEPs' regardless of position

/*[local-name()='HOEP'][1] = Return all children with name 'HOEP' that have the position 1

/*[local-name()='Price'] = Return all children named 'Price'



The XML Import uses the Microsoft XML tools.

Below is a useful website containing useful Xpath information in the form of a tutorial. Select the "Next Chapter" link to start the tutorial.

http://www.w3schools.com/xpath/xpath_intro.asp