If you do the try to set the timestamp AFTER the Update the record is already written and your change would
not be refected. THAT is the difference between BEFORE and AFTER as I understand it.
Radoslaw Stachowiak wrote:
> *** Stephan Szabo <sszabo@megazone23.bigpanda.com> [Wednesday, 17.October.2001, 12:04 -0700]:
> > create function adresses_trigger() returns opaque as '
> > begin
> > NEW.date_maj := now();
> > return NEW;
> > end;' language 'plpgsql';
> > create trigger tr before update on adresses for each row execute
> > procedure adresses_trigger();
>
> why sould I use before (instead of after)?
> isnt it a little dangerous in transactions? /hope not/
>
> I know difference between both forms. The question is rather about if
> timestamp updating shouldnt be run AFTER update which I think is closer
> to a real world situations (of course evth vary). But maybe there are
> some probles with after, which I dont know about?
>
> Just being curious...
>
> --
> radoslaw.stachowiak.........................................http://alter.pl/
>
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