Error handling inside Triggers

[KingElves]

Hello.
I'm trying to use a "raise_application_error" inside a trigger to halt all execution and return an error. It's not working though, here is what i got:

CREATE OR REPLACE TRIGGER iva_trigger
BEFORE
INSERT OR UPDATE OF cat_iva,descrição,imposto ON Iva FOR EACH ROW

DECLARE

...
...
IF (cat_aux=:new.cat_iva) THEN
RAISE categoria_existente;
END IF;
EXCEPTION
WHEN categoria_existente THEN
RAISE_APPLICATION_ERROR(-20001,'....');

This trigger is being called by a function i defined in a package, just before an INSERT command. The problem is, instead of halting execution, it returns to the aforementioned function, and tries to execute the INSERT command.
Obviously, i don't want to execute this INSERT, since it will violate a PRIMARY KEY constraint.
Why isn't this EXCEPTION working?
How do i do it?

Thanks all!

 

[Advocate]

My recent work with exceptions using systems error codes has shown me that i need to declare the exception using PRAGMA EXCEPTION before i can use it eg :

--********************************************************
--Added by ... 9 Oct 2000

e_Legacy EXCEPTION; -- error handler for multiple legacy client numbers
PRAGMA EXCEPTION_INIT(e_Legacy, -1422); -- tie error handler to
-- ORA-01422: exact fetch returns more than requested number of rows

e_LegacyClntNo EXCEPTION; -- error handler for unique constraint violation
PRAGMA EXCEPTION_INIT(e_LegacyClntNo, -1); -- tie error handler to ORA-01
--**************************************************************

Would this be the case for your particular requirements ?
Best of Irish Luck, David.
djwilkes@hotmail.com