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