Re: unique constraint on 2 columns - Mailing list pgsql-general

From Jorge Godoy
Subject Re: unique constraint on 2 columns
Date
Msg-id 87647qpxj9.fsf@gmail.com
Whole thread Raw
In response to unique constraint on 2 columns  (Jonathan Vanasco <postgres@2xlp.com>)
Responses Re: unique constraint on 2 columns  (Vladimir Zelinski <zelvlad@yahoo.com>)
List pgsql-general
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>

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