Re: unique constraint on 2 columns

Jonathan Vanasco <postgres@2xlp.com> writes:

> I need a certain unique constraint in pg that i can't figure out.
>
> Given:
>
>     create table test_a (
>         id serial ,
>         name_1 varchar(32) ,
>         name_2 varchar(32)
>     );
>
> I need name_1 and name_2 to both be unique so that:
>     name_1 never appears in name_1 or name_2
>     name_2 never appears in name_2 or name_1
>
>
> a standard 2 column unique index / constraint will not accomplish this.

But a trigger will...

--
Jorge Godoy      <jgodoy@gmail.com>