Re: [HACKERS] Re: Comparisons on NULLs (was Re: A small problem...)

On Tue, 3 Nov 1998, D'Arcy J.M. Cain wrote:

> Thus spake Tom Lane
> > >> but I can see the reasonableness of defining "3 != NULL" as TRUE.
> > 
> > > Actually I see it as FALSE.  That's what I was suggesting earlier.  All
> > > comparisons to null should be false no matter what the sense of the
> > > test.
> > 
> > Hmm.  That yields extremely unintuitive results for = and !=.  That is,
> > 
> >     SELECT * FROM t WHERE b = NULL;
> > 
> > will never return any rows, even if there are some where b is null;
> 
> Hmmm.  That would be a problem.  Of course, we could treat the null
> value at the higher level too.  I guess that's why we have the "IS
> NULL" syntax in the first place.  It is different than comparing the
> actual values.
> 
> Marc, how long can we hold 6.4 while we work this all out?
How long can we hold *what*?  Is this a new bug that didn't exist
in previous version of PostgreSQL?  

Marc G. Fournier                                
Systems Administrator @ hub.org 
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org