The firebird rdb$fields stores nullability value of the domain/column. Then the rdb$relation_fields ALSO store the nullability value of the domain/column (this looks like the actual override). So firebird still doesn't support overriding the not null constraint on the domain???

--- In firebird-support@yahoogroups.com, W O <sistemas2000profesional@...> wrote:
>
> The only way that I know is allowing the domain to have nulls and puting not
> null on the columns.
>
> Regards.
>
> Walter.
>
>
>
> On Fri, Sep 9, 2011 at 6:34 PM, firebirdsql <firebirdsql@...> wrote:
>
> > **
> >
> >
> > I have the following ddl:
> > CREATE DOMAIN test_domain VARCHAR(25) NOT NULL;
> >
> > However, for one of the tables column that use this domain, the column can
> > be null. How can I override the domain NOT NULL constraint?
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>