triggers in SQL?

I want to write a simple trigger in SQL (i.e. use the trigger to execute
a simple function written in SQL). I'm having difficulty - CREATE TRIGGER
complains if the return type of the procedure is not 'OPAQUE', but CREATE
FUNCTION won't allow me to create SQL functions with a return type of
OPAQUE.

Am I going about this the wrong way? I want to update some data
automatically when new rows are inserted into table A. Should I use a
TRIGGER AFTER INSERT on table A, or is there a better way? The data
that needs to be updated is fairly simple (actually, just 1 or 2
UPDATE queries), which is why I would prefer not to have to load PL/SQL
or write the function in C.

Thanks, and sorry for my newbie-ness.

Neil

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Neil Conway <neilconway(at)home(dot)com>
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