Do you know if the alias is required on the table1?

etc:
CHECK(EXISTS(
SELECT * FROM table1 WHERE type = new.type;
));

--- In firebird-support@yahoogroups.com, Ann Harrison <aharrison@...> wrote:
>
> On Thu, Sep 22, 2011 at 8:05 PM, firebirdsql <firebirdsql@...> wrote:
>
> > I have the following check constraint for table1:
> > EXISTS
> > (
> > SELECT * FROM table1 AS a WHERE a.type = type;
> > );
> >
> > The problem with this is that the right side of the assignment operator,
> > type, refers to a.type instead of the new record's type. Sometimes it refers
> > to the record's type, sometimes it refers to a.type and it depends on the
> > table.
> >
> > To fix it, I have to do WHERE a.type = table1.type.
> >
>
> The alias for values in the new record is new, as in
>
> EXISTS
> (
> SELECT * FROM table1 AS a WHERE a.type = new.type;
> );
>
> And I hope the "=" is intended to be an equality operator, not an assignment
> operator. We're speaking SQL here, not C.
>
>
> Good luck,
>
> Ann
>
>
> [Non-text portions of this message have been removed]
>