Re: ERROR: UNIQUE constraint ... not found?

Which record in the parent table would the foreign key refer to if there were
multiple (non unique) records with the same value in the referenced table?

Ed L. wrote:
> On Wednesday April 2 2003 3:31, Ed L. wrote:
>
>>Well, I've stared at this little riddle for long enough.  Anyone see a
>>mistake?
>>
>>CREATE TABLE person (
>>        id      SERIAL,
>>        name    VARCHAR NOT NULL
>>);
>>
>>CREATE TABLE session (
>>        id                      SERIAL,
>>        person_id               INTEGER NOT NULL,
>>        FOREIGN KEY (person_id) REFERENCES person (id)
>>);
>>
>>psql:test.sql:12: ERROR:  UNIQUE constraint matching given keys for
>>referenced table "person" not found
>
>
> Ah.  I was wondering why this didn't work anymore when it worked in 7.1.  I
> guess the change in SERIAL semantics where the unique index is no longer
> created is what causes the problem.  If I used PRIMARY KEY or create a
> unique index manually on person.id, it works fine.  It seems odd that one
> cannot have a foreign key to a non-indexed column in another table.
>
> Ed
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster
>