Update the passed XML in a PL/SQL procedure and then use DBMS_XMLSAVE

Question

hi folks,
This is a great forum and most of you guys were awesome in replying to complex queries........
I have a small issue, I am trying to do a bulk insert from my application by constructing an XML result set and pass that XML to the SP as a CLOB and using DBMS_XMLSAVE package to insert it to the oracle table. It works like a charm for me when this is as straight forward as this. But when my requirement is, I need to generate sequence numbers for a particular column (Primary key column), while for other columns I pass values from the UI (as a XML object which my SP accepts as a CLOB), i am at a loss for solution to achieve this. It would mean, that I have to generate the sequence numbers for each row and then update this value to the passed XML clob. Any indicators on how to achieve this?
I found this solution at one of the thread which might most probably help me,
declare
2 l_cnt number;
3 begin
4 select count(*) into l_cnt from books,xmltable('/Books/Book' passing object_value);
5 for i in 1..l_cnt loop
6 update books set object_value =
7 updatexml(object_value,'/Books/Book['||i||']/BookID', xmlelement("BookID",sequence_bookid.nextval))
8 where existsnode(object_value,'/Books/Book['||i||']')=1;
9 end loop;
10 end;
11 /
But here, they are trying to update a XMLTable book, but in my case the XML is a clob object and not a XML table. Will this solution work for my case as well? Please provide any pointers to me... Thanks...

Answer 1

First if your version of Oracle has DBMS_XMLSTORE, use that instead.
Reason: {thread:id=876376} (See Marco's response).
It is possible you could run into issues, but you should start with DBMS_XMLSTORE.
Since you will have the XML in the SP, treat the data as an XMLType instead of a CLOB for as long as you can since you need to do UpdateXML on it.
For your sample PL/SQL code, lines 4-5 are replaced with the WHILE loop shown in Method 2 at
{message:id=3610259}.
The UPDATE would be replaced with the following pseudocode
SELECT UPDATEXML(<l_xmltype_variable>, ...)
INTO <l_xmltype_variable>
FROM dual;
Once your loop is done, l_xmltype_variable would contain your updated XML and then you can use that XMLType directly on the call to DBMS_XMLSTORE or convert it back to a clob via
l_clob_variable := l_xmltype_variable.getClobVal();