Jonathan Vanasco <postgres(at)2xlp(dot)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(at)gmail(dot)com>