Re: [SQL] NULL

Bruce Momjian wrote:

> [Charset iso-8859-1 unsupported, filtering to ASCII...]
> >
> > How about this according to SQL standard:
> >
> > CREATE TABLE x { y integer NULL };
> >
> > It suppose to mean that NULLs are explicitly allowed in
> > this field.
> > Is this required by SQL-92?
>
> If I remember correctly, only NOT NULL is supported by SQL-92.  Thomas
> talked about adding support for it in some limited cases for 7.0.  There
> are shift/reduce cases if it were allowed everywhere.

Hmmm,

    I can't see any shift/reduce conflicts if I place a

        | NULL_P

    case into the ColConstraintElem: definition right between the

        | DEFAULT b_expr

    and

        | NOT NULL_P

    cases. Could it be that this reason is out of date?


Jan

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