Re: alter table and constraints

On Fri, 25 Aug 2000, Martin A. Marques wrote:

> On Fri, 25 Aug 2000, Peter Eisentraut wrote:
>
> > Martin A. Marques writes:
> >
> > > I don't know if this is posible, but I'm trying to add and delete
> > > constrains from a table. Is this posible and why am I having so much
> > > problems?
> >
> > Because it only works for foreign keys. If you are talking about foreign
> > key contraints then you should define "problems" better.
>
> No, it was a primary key.
> Can I change the constraint of NULL in a column? And what should I do if
> I want to add a primary key to a table?

Well, you can add a unique index to the columns and set attnotnull in
pg_attribute which should probably work for the not null portion. That's
basically what the primary key constraint is.