Re: [HACKERS] Re: NULL & NOT NULL

> > > The "Practical SQL Handbook"-compatible form will be available in 
> > > the next full release of Postgres. Thanks.
> > Now that we have the syntax problem straightened out: I'm still 
> > confused about the semantics.
> Can be null.  Noise word.  At least that is what I rememeber Thomas
> saying, and because it was noise, we removed it.  In fact, it doesn't
> look like the standard accepts it, but there is no reason we can't.

Yeah, it's noise. And not in SQL92. I've flagged places in gram.y which
are syntax extensions included just to be compatible with specific
products so that if we ever run into parser conflicts with them we can
yank them out. The M$ usage for "where var = NULL" rather than the SQL
standard usage "where var is null" is another example of this.

I don't own "The Practical SQL Handbook", but it is funny that it
contains examples which are not part of the SQL standard (this is the
second one as I recall; can't remember the first one though).
                        - Tom