The following bug has been logged online:
Bug reference: 1636
Logged by: Fredrik Olsson
Email address: peylow@atari.org
PostgreSQL version: 8.0.2
Operating system: Max OS X 10.3.9
Description: Foreign key referencing inherited table fails.
Details:
Some SQL statements says more then 1000 words :).
CREATE TABLE employees (
nr serial PRIMARY KEY,
name varchar(32)
);
CREATE TABLE managers (
loves_meetings boolean DEFAULT TRUE NOT NULL
) INHERITS (employees);
CREATE TABLE events (
summoner integer NOT NULL REFERENCES employees (nr),
at timestamp DEFAULT now() NOT NULL,
reason text NOT NULL,
PRIMARY KEY (summoner, at)
);
INSERT INTO employees (name) VALUES ('Bob');
INSERT INTO managers (name) VALUES ('Alice');
-- This makes an ugly assumption of nr starting at 1 and Alice having nr=2.
INSERT INTO events (summoner, reason) VALUES (2, 'Brag about
inheritance.');
The last statement will fail with this error message:
ERROR: insert or update on table "events" violates foreign key constraint
"events_summoner_fkey"
DETAIL: Key (summoner)=(2) is not present in table "employees".
The foreign key from events (summoner) referencing employees (nr) can be
removed and replaced by triggers with ease. But I still think it is a bug,
and that foreign key references to tables that are inherited from should be
legal, even if referenced rows orginates from child tables.