Item Level Validation Not Working As Supposed To...

Question

Hi All,
I have an item validation type: SQL(Not Exist) that checks whether the value in the id number field exists in the database when Create button is clicked. If the id number exists in the database then an error message is displayed in line with the field & the transaction doesn't go through; however, when this happens Apply Changes & Delete button appear & Create button dissapear. It's as if the record has already been inserted. I would like this validation to work like the Not Null validations.
I repeated this process several times without success & now I can't even create a new user or update & delete existing ones - I get the error:
ORA-06550: line 1, column 7: PLS-00428: an INTO clause is expected in this SELECT statement
ORA-2015: User ID number already exists in the database.NB:The second message is the one I use whenever there's duplicates so, it's oracle reserved message. Any help is highly appreciated.
Regards
Kamo

Answer 1

The buttons probably have conditions to appear if a certain item is not null. You can set this item to null as part of the validation, e.g.,
:P1_X := null;
...but to do that you'd need to change the validation type to PL/SQL Function Returning Boolean and code the "not exists" logic into the PL/SQL block.
Scott