Re: [HACKERS] Subselects and NOTs

> Added to TODO.
> > ... In Postgres, a column can be
> > designated "not null", the default being to allow nulls.  In the
> > default Sybase configuration, it is the other way around.  In the
> > interest of writing cross database compatible code, I try to always
> > call out columns as either "null" (nulls allowed), or "not null"
> > (nulls not allowed).  Unfortunately, Postgres does not support this
> > In short, it would be nice if Postgres would take "null" as a type
> > specifier as well as "not null".

We currently get a shift/reduce parsing conflict on this since NULL can be
specified in other constraint clauses and since the constraint clauses are
only whitespace delimited. It might be that this part of the parser can be
redone, or perhaps the only way around is to restrict the ordering of the
constraints. But NULL constraint is not SQL92 and free ordering is...

                                                       - Tom