Re: how to rename an unnamed uniqueness constraint?

On Tue, Aug 16, 2005 at 11:11:23PM +0100, Oliver Elphick wrote:
> On Tue, 2005-08-16 at 19:01 +0100, Oliver Kullmann wrote:
> >
> > I have a table created with
> >
> > CREATE TABLE Current_academic_year
> > (
> >     year_id        INT    REFERENCES Academic_years,
> >     CONSTRAINT year_id CHECK(year_id IS NOT NULL),
> >     active        BOOL    NOT NULL,
> >
> >     UNIQUE(year_id),
> >     UNIQUE(active)
> > )
> > ;
>
> > Now I need to drop the constraint "UNIQUE(active)".
> > I tried variations of
> >
> > ALTER TABLE current_academic_year DROP CONSTRAINT "???"
> >
> > but I didn't succeed.
> >
> > I'm using version 7.4.8.
> >
> > Thanks in any case for your efforts!
>
> \d current_academic_year
>
> would show you that you have an index called
> current_academic_year_active_key to enforce the unique constraint.
>
>   junk=# DROP INDEX current_academic_year_active_key;
>   ERROR:  cannot drop index current_academic_year_active_key because constraint current_academic_year_active_key on
tablecurrent_academic_year requires it 
>   HINT:  You may drop constraint current_academic_year_active_key on table current_academic_year instead.
>
> Therefore, what you need to do is:
>
> ALTER TABLE current_academic_year DROP CONSTRAINT current_academic_year_active_key;
>

Thanks, that worked!

> TIP 3: Have you checked our extensive FAQ?
>                http://www.postgresql.org/docs/faq
>

aha, looks good. I've added it to my bookmarks.

Oliver