Re: Update on tables when the row doesn't change

On 5/25/05, Sebastian Böck <sebastianboeck@freenet.de> wrote:
> >>CREATE OR REPLACE FUNCTION upd (view_test) RETURNS VOID AS $$
> >>        DECLARE
> >>                NEW ALIAS FOR $1;
> >>        BEGIN
> >>                RAISE NOTICE 'UPDATE';
> >>                UPDATE test SET test = NEW.test WHERE id = OLD.id;
> >>                UPDATE join1 SET text1 = NEW.text1 WHERE id = OLD.id;
> >>                UPDATE join2 SET text2 = NEW.text2 WHERE id = OLD.id;
> >>                UPDATE join3 SET text3 = NEW.text3 WHERE id = OLD.id;
> >>                RETURN;
> >>        END;
> >>$$ LANGUAGE plpgsql;
> >
> >
> > Control question, I didn't check it, but would it be enough to change from:
> >    UPDATE join1 SET text1 = NEW.text1 WHERE id = OLD.id;
> > to:
> >    UPDATE join1 SET text1 = NEW.text1 WHERE id = OLD.id AND text1 <> NEW.text1?
> >
> > ...  I may be wrong. :)
>
> Yes, thats more elegant then my other (4th) solution.
> Was late yesterday evening ;)

Be wary of the NULL values though. :)  Either don't use them, add
something like 'AND (text1 <> NEW.text1 OR text1 IS NULL OR NEW.text1
IS NULL)' or something more complicated. :)

   Regards,
         Dawid