Re: ALTER TABLE & NOT NULL

On Sat, 6 Apr 2002, Joe Conway wrote:

> Thomas T. Thai wrote:
> > How do you alter a column so that it uses NOT NULL? I tried:
> >
> > alter table auth_users alter email set default not null;
> >
> > ERROR:  Column "email" is of type character varying but default expression
> > is of type boolean
> >         You will need to rewrite or cast the expression
> >
>
> I think you have to add a table constraint to do that. Something like:
>
> ALTER TABLE auth_users ADD CONSTRAINT auth_users_email CHECK (email is
> not null);

is this also what happens at the time of table creation when one specifies
that a column is to be NOT NULL?