Re: Constants in the foreighn key constraints

On 11/22/19 11:36 PM, aleksey ksenzov wrote:

Please reply to list also.
Ccing list.

> We're already on 12.
>
> While I understand I can do everything with triggers/functions, for me
> it looks like a good idea to have possibility to use constants in
> constraints, so it would be very nice if postgres community could add
> this functionality in the nearest releases.
> Regards,
> Aliaksei.
>
>
> On Fri, Nov 22, 2019 at 4:25 PM Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>> wrote:
>
> On 11/22/19 6:32 AM, aleksey ksenzov wrote:
> > Hi team.
> > Latest time we faced several issues which wouldn't arise provided we
> > have possibility to use constants in foreign key constraints.
> > brief example where it would be helpful:
> >
> > table_a
> > ( id uuid,
> > parent_id uuid,
> > is_deleted boolean
> > )
> > having possibility of FK (parent_id, false) to (id, is_deleted)
> > would disallow setting parent record deleted flag to true if they
> have
> > children, or insert record with is_deleted = true parent.
>
> Postgres version?
>
> Look at triggers, in particular CONSTRAINT triggers:
>
> https://www.postgresql.org/docs/12/sql-createtrigger.html
>
> >
> > Regards,
> > Aliaksei.
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com