Re: NULL != text ?
От | Alban Hertroys |
---|---|
Тема | Re: NULL != text ? |
Дата | |
Msg-id | 43576D09.9090305@magproductions.nl обсуждение исходный текст |
Ответ на | Re: NULL != text ? (Michael Glaesemann <grzm@myrealbox.com>) |
Ответы |
Re: NULL != text ?
Re: NULL != text ? |
Список | pgsql-general |
Michael Glaesemann wrote: > if (OLD.value IS NOT NULL and NEW.value IS NOT NULL and OLD.value <> > NEW.value) or OLD.value IS NULL or NEW.value IS NULL > > But that's untested and I have a hard time thinking in three-value logic. For completeness sake; Because of lazy evaluation, that boils down to: if (OLD.value IS NULL OR NEW.value IS NULL OR OLD.value <> NEW.value) The last part of the expression is only evaluated if both OLD.value and NEW.value aren't NULL. -- Alban Hertroys alban@magproductions.nl magproductions b.v. T: ++31(0)534346874 F: ++31(0)534346876 M: I: www.magproductions.nl A: Postbus 416 7500 AK Enschede //Showing your Vision to the World//
В списке pgsql-general по дате отправления: