On Sat, 11 Dec 2004, Vitaly Belman wrote:
> I have the following code in one of my trigger functions
>
> ---------------------------------------------------------------
> IF old.series_id<>new.series_id THEN
> ...
> ...
> END IF;
> ---------------------------------------------------------------
>
> The problem is that series_id can change to be NULL in which case I
> have problems as "NULL <> 7" doesn't return "true".
old.series_id IS DISTINCT FROM new.series_id may do what you want
depending on how you want NULLs to compare (IS DISTINCT FROM would be
false).