Update XML value in stored in Clob - oracle

Question

Does anyone know a solution how I can change a specific value within xml? XML is stored in Clob datatype.
My XML looks like:
<settings name="TEST_NAME" path="TEST_PATH">
<values>
<value param="Version">20200207</value>
</values>
<collections>
<collection name="Items">
<values>
<value param="TEST_PARAM">true</value>
</values>
<collections>
</collection>
<collection name="TEST_COL">
<values>
<value param="DockedLeft">0</value>
</values>
<collections>
<collection name="ItemLink0">
<values>
<value param="ItemName">TEST_PARAM</value>
</values>
</collection>
</collections>
</collection>
</collection>
</collections>
What I need to update is "TEST_PARAM" inside TEST_COL collection. Collection name itemlink0 can be different. Thanks for the answers!

Answer 1

I created some sample XML that is valid and inserted into a CLOB column. It should suffice to show how this can be done using XMLQuery and a SQL update.
CREATE table xml_tbl (xml_str CLOB)
INSERT INTO xml_tbl VALUES(
'<settings name="TEST_NAME" path="TEST_PATH">
<collections>
<collection name="TEST_COL">
<values>
<value param="DockedLeft">0</value>
</values>
<collections>
<collection name="ItemLink0">
<values>
<value param="ItemName">TEST_PARAM</value>
</values>
</collection>
</collections>
</collection>
</collections>
</settings>')
The element value can be updated by converting the CLOB to/from XMLType and utilizing XMLQuery to update the XML. The element having the dynamic attribute name can be a PL/SQL variable within the PASSING clause of the XMLQuery.
DECLARE
l_dyn_attr_name VARCHAR2(100):= 'ItemLink0';
l_element_value VARCHAR2(100):= 'new value';
BEGIN
UPDATE xml_tbl xt
SET xt.xml_str =
XMLTYPE.GETCLOBVAL(XMLQuery('copy $i := $x1 modify
(for $j in $i/settings/collections/collection[#name="TEST_COL"]/collections/collection[#name=$dynamic_attr_name]/values/value
return replace value of node $j with $new_elem_value)
return $i' PASSING XMLTYPE(xt.xml_str) AS "x1"
,l_dyn_attr_name AS "dynamic_attr_name"
,l_element_value AS "new_elem_value" RETURNING CONTENT));
COMMIT;
END;