Put ID attributes on all nodes

Question

Hello
I have an XML similar to this
<root>
<elem>
<subElem>
</subElem>
</elem>
<elem>
<subElem>
</subElem>
<subElem>
</subElem>
</elem>
</root>
I'm trying to put a lot of "Id" attributes on each element for easy acces. I want a result like
<root>
<elem id="1">
<subElem id="1">
</subElem>
</elem>
<elem id="2">
<subElem id="1">
</subElem>
<subElem id="2">
</subElem>
</elem>
</root>
So I can acces the second "sub" in the second element as /root/elem/@id="2"/sub/@id="2"
Do you have any way to put that "Id" attributes using XQuery or another way. I prefer a non programmatic method (that is, using Oracle, not Java).
I've tried with InsertChildXML function in this way
update xmlTable
set xmlField = insertChildXML (xmlField, '/root//*','@id','nothing');
That works, but, how I can put the Id numbers for each element and subelement?
Another way is using XQuery, but at now, I'm getting poor results.
Any help?
Thanks.
José Domingo Hernández
Edited by: jdhernandez on Sep 2, 2009 8:28 AM

Answer 1

Without knowing all the details of why you are trying to add an id attribute, beyond "easy access", why not just use an XPath like
/root/elem[2]/subElem[2]
instead of
/root/elem/@id="2"/sub/@id="2"
Using either XML, my Xpath says to get the second subElem within the second elem within the root node. This agrees with what yours asks for, on the assumption that nothing reorders the XML during your processing.