Problem using views containing xpath expressions with Oracle Forms

Question

Mark,
Nice to see you back on the forum answering questions.
This example is based on the standard purchaseorder schema.
i registered the schema, created a relational table and then created
a view using xpath.everything works well and i am able to select the data
using sql*plus. Now this views is like any other view, when i describe the
view, i can see the all the data types are valid for the columns and also the lengths.
Now when i try to base a data block in oracle forms using this view, i get error
"ORA-24324 - service handle not initialized."
Whereas if i create another view on top of the first view and then base the data block on this view, it works for me. i described the second view from sql*plus and everything seems to be same for me.
this is the same behaviour from database 9i r2 and it exists in 10g r1 also.
Any hints as what might be the problem or you would like me to file a tar for this.
create or replace view purchaseorder_header_xml
as
select  id
       ,extractvalue(xml_data, '/PurchaseOrder/Reference') reference
       ,extractvalue(xml_data, '/PurchaseOrder/Requestor') requestor
       ,extractvalue(xml_data, '/PurchaseOrder/User')      po_user
       ,extractvalue(xml_data, '/PurchaseOrder/CostCenter') costcenter
       ,extractvalue(xml_data, '/PurchaseOrder/SpecialInstructions') spl_instructions
from tab_xmldata
create or replace view purchaseorder_header
as select * from purchaseorder_header_xml
/Raghu

Answer 1

Not used Forms for years. However I suspect that Forms is trying to poke around behind the view and not understanding what it sees. I expect you'll need to open a Forms Tar to get to the bottom of this. It also appears that you a workaround which is to create a view on the view by the sound of it..