On Monday 17 March 2008 4:54 am, Daniel Verite wrote: > Adrian Klaver wrote: > > CREATE FUNCTION foo() RETURNS trigger AS > > $Body$ > > BEGIN > > IF NEW.colname != OLD.colname THEN > > ..."Do something"..; > > RETURN whatever; > > ELSE > > RETURN NEW: > > END IF; > > END; > > $Body$ LANGUAGE plpgsql; > > Beware that the "Do something" code path will not be taken when the > column goes from NULL to non-NULL or non-NULL to NULL. > > In the general case where the column is nullable, better use "IS > DISTINCT FROM" instead of inequality: > IF NEW.colname IS DISTINCT FROM OLD.colname > > Best regards, > -- > Daniel > PostgreSQL-powered mail user agent and storage: > http://www.manitou-mail.org Thanks for the heads up. This is a case I usually only remember when I start testing the function. -- Adrian Klaver aklaver@xxxxxxxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
