Problem while using Before insert Trigger

Question

Hello everybody,
I am using 9.2.0.4.0 XMLDB..
The problem occurs while using the before insert trigger shown below to convert a CLOB(:new.file_clob) to XMLTYPE(:new.file_xml). The trigger is on a table with file_clob and file_xml as columns. file_xml column is based on a registered schema.
The trigger is:
Create or replace trigger po_2_demo_xml_tab_trg
before insert on po_2_demo_xml_tab
FOR EACH ROW
-- Step 1:to convert CLOB to XMLtype and store it
--in :new.file_xml .
:new.file_xml := xmltype(:new.file_clob);
-- Step 2:to verify if :new.file_xml has been created
dbms_output.put_line(:new.file_xml.extract('/PurchaseOrder/PONum/text()').getStringVal());
end;
If u insert a valid xml file, u can see the PONum value on dbms output(Step 2 of the trigger works). u also get the "1 row inserted" message.
Surpisingly, if u query on the table it shows that the file_xml column is null! For some reason, the value of :new.file_xml in the before insert trigger is not being retained in the table.
Has anybody encountered this before? Do I have to apply any patch?
Appreciate any help in this regard.
Thanks,
Partha.

Answer 1

sorry! I just noticed.. the trace file does show an error, but the error is while creating the table itself.
Please see the segment from trace file below:
The following statements encountered a error during parse:
create table po_2_demo_clob_xml_tab
file_clob CLOB,
file_xml xmltype
)xmltype column file_xml
XMLSCHEMA "http://Friday/PO_2.xsd"
ELEMENT "PurchaseOrder";
XCTEND rlbk=0,
Error encountered: ORA-00911
But, inspite of this I am able to insert a xml file into file_xml using a sql statement. But the before insert trigger does not retain :new values.
Appreciate any comments.
Thanks,
Partha.