Re: Trigger plpgsql function, how to test if OLD is set?

Dnia 2003-12-04 19:18, Użytkownik Jeff Kowalczyk napisał:
> When this trigger runs on INSERT operations, the OLD variable is not
> yet set, and the trigger function returns an error.
> 
> Can anyone suggest a more sensible way to check for OLD before including
> it in my expression, or another shortcut? Thanks.
> 
> CREATE OR REPLACE FUNCTION orders_initordercharges () RETURNS "trigger"
>     AS '
> BEGIN
>   -- Check that no ordercharges exist for this orderid
>   IF (SELECT COUNT(orderchargeid) FROM ordercharges WHERE orderid=NEW.orderid OR orderid=OLD.orderid)=0 THEN
>     -- Insert standard initial set of ordercharges
>     INSERT INTO ordercharges (orderid, orderchargecode) VALUES (NEW.orderid,\'SALE\'); 
>     INSERT INTO ordercharges (orderid, orderchargecode) VALUES (NEW.orderid,\'S&H\'); 
>   END IF;
>   RETURN NEW;
> END;
> '
>     LANGUAGE plpgsql;

You can always check whether your trigger has been fired as insert or 
update trigger.

DECLARE  old_orderid  integer;
BEGIN  if TG_OP=''UPDATE'' then     old_orderid=OLD.orderid;  else     old_orderid=-1;  end if;
...

Regards,
Tomasz Myrta