Re: PL/pgSQL return value in after triggers

On Mon, Feb 28, 2011 at 12:07 PM, Peter Eisentraut <peter_e@gmx.net> wrote:
> PL/pgSQL trigger functions currently require a value to be returned,
> even though that value is not used for anything in case of a trigger
> fired AFTER.  I was wondering if we could relax that.  It would make
> things a bit more robust and produce clearer PL/pgSQL code.  The
> specific case I'm concerned about is that a trigger function could
> accidentally be run in a BEFORE trigger even though it was not meant for
> that.  It is common practice that trigger functions for AFTER triggers
> return NULL, which would have unpleasant effects if used in a BEFORE
> trigger.
>
> I think it is very uncommon to have the same function usable for BEFORE
> and AFTER triggers, so it would be valuable to have coding support
> specifically for AFTER triggers.  We could just allow RETURN without
> argument, or perhaps no RETURN at all.
>
> Comments?

It has bugged me for years that after triggers need to contain a
useless RETURN statement, but I'm not sure now is the time to go fix
it.

--
Robert Haas
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