XML getElementByTagName Path - oracle

Question

I have some XML like:
<?xml version="1.0" encoding="ISO-8859-1"?>
<rss version="2.0">
<channel>
<title>List of Users</title>
<description>This is the list of users in the system</description>
<item>
<cgId>2488962</cgId>
<externalId>2021111</externalId>
<externalUid></externalUid>
<deactivated>0</deactivated>
<firstName>Nat</firstName>
<lastName>Pul</lastName>
</item>
</channel>
</rss>
I'm trying to use PL/SQL to loop through the "item" tags only...I don't want to deal with the "channel", "title", etc. I can loop through ALL the tags using "*" but when I try to use a path to "item" I get nothing...(see code snippet below). Is there a way to do this?
-- lv_temp_lob has the XML in it...
lv_xmlResponse := XmlType( lv_tmp_lob );
DBMS_LOB.FreeTemporary( lv_tmp_lob );
lv_xmldoc := DBMS_XMLDOM.newDOMDocument(lv_xmlResponse);
lv_nodelist := DBMS_XMLDOM.getElementsByTagName(lv_xmldoc, '//channel/item'); -- THIS???
FOR i IN 0..DBMS_XMLDOM.getLength(lv_nodelist) -1
LOOP
lv_node := DBMS_XMLDOM.item(lv_nodelist, i);
testr := DBMS_XMLDOM.getNodeName(lv_node) || ' ' || DBMS_XMLDOM.getNodeValue(DBMS_XMLDOM.getFirstChild(lv_node));
DBMS_OUTPUT.PUT_LINE (testr);
END LOOP;
DBMS_XMLDOM.freeDocument(lv_xmldoc);

Answer 1

getElementsByTagName() takes, as its name suggests, a node name - not a path.
So you could just look for all item nodes with:
lv_nodelist := DBMS_XMLDOM.getElementsByTagName(lv_xmldoc, 'item');
db<>fiddle
If you have a structure with item nodes under different parents and you only want those under channel nodes then you can find the channel nodes, then look for item nodes under those, in more nested loops.
Depending on what you are doing and the stability of the XML structure you have to deal with, you might find it simpler to extract the information through XMLTable.