On Thu, Jul 25, 2013 at 3:02 PM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > Luca Ferrari <fluca1978@xxxxxxxxxxx> writes: >> The original post was related to the update of b, so I guess it is >> better to limit the trigger scope to update on such column: > >> CREATE OR REPLACE FUNCTION b_mirror() RETURNS TRIGGER AS >> $mirror$ >> BEGIN >> NEW.a = NEW.b; >> RETURN NEW; >> END; >> $mirror$ LANGUAGE plpgsql; > >> CREATE TRIGGER tr_b_mirror AFTER UPDATE OF b ON cats FOR EACH ROW >> EXECUTE PROCEDURE b_mirror(); > >> It is worth noting that the trigger could be an after one, > > No, it has to be a BEFORE trigger, else it's too late to affect the > row value that gets stored. Ops..I wrote it without my brain with me: of course it has to be a before one. Thanks, Luca -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
