Adding an attribute to some pre-existing XML

Question

Hi all,
I have a table with some small XML documents in a CLOB column and i'd like to add an attribute to one of the elements using SQL. Neither the table nor the XML is "mine" so I can't make any significant changes to the structure or current content - I just want to add this one attriibute.
For example a row has this value in the CLOB column :
<?xml version="1.0"?>
<product>
<detail>
<supplier id="12345"/>
</detail>
</product>
and i'd like to add a "test" attribute to the <product> element, like this :
<?xml version="1.0"?>
<product test="yes">
<detail>
<supplier id="12345"/>
</detail>
</product>
I'd hoped updateXML would do it like this, but it won't (unless the attribute already exists, which alas it doesn't always) :
select updatexml(xmltype(my_xml_column), '/product/@test', 'yes') new_xml
from my_table
Can anyone help me here? I've not really delved too deeply into Oracle's XML (or XML generally for that matter) and just need to perform this simple update!
Thanks,
Steve

Answer 1

Thanks for this. I had looked (briefly!) at this package but it did seem a little over complicated for what i wanted - ideally I just wanted to write a SQL statement to do it all.
Is there not a simpler way?
Steve