The following bug has been logged online:
Bug reference: 2122
Logged by: David Wheeler
Email address: david@justatheory.com
PostgreSQL version: 8.1.0
Operating system: Mac OS X 10.4.3
Description: Inconsistent FK Error Messages
Details:
I noticed that when I update or insert a record that violates a foreign key
constraint, I get an error such as 'insert or update on table "b" violates
foreign key constraint "b_a_id_fkey"', but when I delete a record where the
primary key is referenced as a foreign key elsewhere, and the FK constraint
is RESTRICT, I get an erro such as 'update or delete on "a" violates foreign
key constraint "b_a_id_fkey" on "b"'. The bit that's inconsistent between
them is that the former says 'table "b"' while the latter just says
'"a"'--no 'table'.
Here's how to reproduce it:
sharky=# create table a (id serial primary key);
NOTICE: CREATE TABLE will create implicit sequence "a_id_seq" for serial
column "a.id"
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "a_pkey" for
table "a"
CREATE TABLE
sharky=# create table b(id serial primary key, a_id int references a(id));
NOTICE: CREATE TABLE will create implicit sequence "b_id_seq" for serial
column "b.id"
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "b_pkey" for
table "b"
CREATE TABLE
sharky=# insert into a (id) values (nextval('a_id_seq'));
INSERT 0 1
sharky=# insert into b (a_id) values(currval('a_id_seq'));
INSERT 0 1
sharky=# insert into b (a_id) values(-1);
ERROR: insert or update on table "b" violates foreign key constraint
"b_a_id_fkey"
DETAIL: Key (a_id)=(-1) is not present in table "a".
sharky=# delete from a;
ERROR: update or delete on "a" violates foreign key constraint
"b_a_id_fkey" on "b"
DETAIL: Key (id)=(1) is still referenced from table "b".
sharky=#
No biggie, but I though it was worth knowing.
Thanks!
