Quoth "Richard Broersma" <richard(dot)broersma(at)gmail(dot)com>:
> On Mon, Dec 1, 2008 at 7:18 AM, Sebastian Tennant
> <sebyte(at)smolny(dot)plus(dot)com> wrote:
>
>> IF (NEW.<column-name> != OLD.<column-name>) THEN ...
>
> The != operator doesn't work the way you might think when nulls are
> thrown into the mix. I asked a similar question a while back and was
> kindly pointed to the following syntax:
>
> IF( NEW.* IS DISTINCT FROM OLD.* ) THEN ...
That's it! Thanks very much Richard.
I sometimes think this kind of gotcha is purposely buried, or not
addressed at all, in order to force users to read the manual. I wasn't
planning on spending four hours doing just that, but now I suppose I'm
almost glad I did.
Sebastian