Enable exception handling in trigger

Question

Hello-
I am fairly new to Oracle, and have written a simple audit trigger to insert old values into an audit table upon updates to an existing table. I am trying to incorporate some exception handling in case there are errors. Is there a way to 'enable' or call out the oracle predefined the errors, or do I have to specifically write conditions for all the exceptions I want to capture?
Thanks!

Answer 1

Hi
There are two types of expections exists in oracle, i.e. internal & external exceptions. Internals are oracle defined and externals are user defined.
Internal
When no_data_found
when too_many_rows
when divide_zero (read oracle documentation for more)
example:
declare
begin
select ename,sal from emp where empno=0;
exception
when no_data_found then
dbms_output.put_line('No such employee exists');
end;
external
=======
you define in the declaretive part
example:
declare
MyException exception
begin
if .... then
raise MyException;
end if;
exception
when Myexception then
do_action
end;