Re: REFERENCES constraint

On Wed, 8 Aug 2001, Cedar Cox wrote:

>
> Two questions (maybe they are silly..)
>
> 1. Can a column reference more than one table? (This assumes you use a
> single sequence to generate the IDs for both "tbla" and "tblb". I guess
> you would also have the problem of enforcing a unique index. Say what?!
> A unique index across multiple tables.. absurd :) eg..
>
> CREATE TABLE blah (
> id int4,
> f_id int4 REFERENCES tbla (id) REFERENCES tblb (id)
> )

Yes, you should be able to do this, but it won't do what you want, it'll
make it be required in both tables. You'll need to do this one by hand.

> 2. Can a column reference another column in the same table? eg..
>
> CREATE TABLE bloo (
> id int4,
> p_id int4 REFERENCES bloo (id)
> -- or
> --p_id int4 REFERENCES (id)
> )

Yes, using your first syntax that should work.