Re: silly NULL question

>>>>> "RT" == "Rod Taylor" <rbt@rbt.ca>:
RT> NULL is similar to UNKNOWN.
RT> 
RT> So, NULL = NULL is the similar to UNKNOWN = UNKNOWN.  Since you don't
RT> know it, how can you tell if they're equal or not?
RT> 
RT> Syntax you're looking for is: AND parent_id IS NULL

ah, of course.  Thanks Rod.

RT> If you really really really need = NULL (due to some MS product which
RT> ignores SQL standards -- say MS Access) there is a toggle in the
RT> postgresql.conf file to allow automated conversion of = NULL to IS NULL
RT> within the server.

ah ha!  the culprit.  I see this was default through 7.1.  Thanks again for
accurate and quick reply.

-dan