What's the state of the art for foreign keys on child tables?
My use case is this:
CREATE TABLE parties(party_id serial primary key);
CREATE TABLE positions( PRIMARY KEY(party_id) ) INHERITS(parties);
CREATE TABLE organizations( PRIMARY KEY(party_id) ) INHERITS(parties);
CREATE TABLE party_names( party_id int REFERENCES parties, surname text, PRIMARY KEY(party_id, surname) );
INSERT INTO organizations VALUES (1);
INSERT INTO party_names VALUES (1, 'foo');
This currently fails with:
ERROR: insert or update on table "party_names" violates foreign key constraint "party_names_party_id_fkey"
DETAIL: Key (party_id)=(1) is not present in table "parties".
CREATE RULE parties_ref
AS ON INSERT TO party_names
WHERE new.party_id NOT IN (SELECT party_id FROM parties)
DO INSTEAD NOTHING;
When using that and no foreign key reference, then the INSERT "succeeds" in inserting 0 records, which doesn't raise an exception... Then I found older posts on this mailing list:
These mention using triggers to reproduce foreign key checks.
Is that information still current as of 9.2?
Thanks!
François
