My first instinct would be to look into triggers. In addition to an FK a(b_id) -> b(id), you could have an insert and update trigger on a(b_id) and b(active) to ensure the additional constraints. On Thu, Aug 18, 2016 at 1:10 PM, Mark Lybarger <mlybarger@xxxxxxxxx> wrote: > I have two tables that i want to link with a FK where the child table record > is "active". > > some googling shows that i could use a function and a check constraint on > the function, but that only works for inserts, not updates on table b. > > create table a (int id, text name); > create table b (int id, boolean active); > > alter table a add column b_id integer; > -- how to do this? > alter table a add foreign key (b_id) references b(id) where b.active == true > > help :). -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
