Re: unique constraint on 2 columns

[Jorge Godoy <jgodoy(at)gmail(dot)com>]

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>