Wednesday, July 2, 2008

Compound Triggers

Seriously, I don't like triggers. But if you have to maintain them, you might as well make the best of it.

While trying to figure out my problem the other day, I ran across Compound Triggers. I hadn't read about it in the 11g New Features guide, but since I don't use triggers, I wasn't sure if it was new or not. Apprently it is...

In essence, you can combine multiple triggers into one. I won't go into the gory details (because I don't know the gory details), but I will provide the example from the docs for your perusal.

CREATE TRIGGER compound_trigger
FOR UPDATE OF sal ON emp
COMPOUND TRIGGER

-- Declaration Section
-- Variables declared here have firing-statement duration.
threshold CONSTANT SIMPLE_INTEGER := 200;

BEFORE STATEMENT IS
BEGIN
...
END BEFORE STATEMENT;

BEFORE EACH ROW IS
BEGIN
...
END BEFORE EACH ROW;

AFTER EACH ROW IS
BEGIN
...
END AFTER EACH ROW;
END compound_trigger;
/
At the very minimum (if you have to use them), you might as well combine them into one and save a bit on maintenance/debugging!

1 comment:

Asif Momen said...

Good piece of information.