Re: Question about NOT NULL and default values.

On Thu, Oct 16, 2008 at 9:58 PM, Tim Uckun <timuckun(at)gmail(dot)com> wrote:
> On Fri, Oct 17, 2008 at 4:40 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> wrote:
>> On Thu, Oct 16, 2008 at 9:09 PM, Tim Uckun <timuckun(at)gmail(dot)com> wrote:
>>> Hey all.
>>>
>>> I am using postgres 8.3 with a rails application. I have a column
>>> defined like this.
>>>
>>> ALTER TABLE provisions ADD COLUMN provider_id integer;
>>> ALTER TABLE provisions ALTER COLUMN provider_id SET STORAGE PLAIN;
>>> ALTER TABLE provisions ALTER COLUMN provider_id SET NOT NULL;
>>> ALTER TABLE provisions ALTER COLUMN provider_id SET DEFAULT 0;
>>
>> Hold on, when did you assign a sequence to this column? When you
>> created it as a serial? Or is there none assigned?
>>
>
> There is no sequence. It's a foreign key.

Not sure what being a FK means here. Postgresql uses sequences and
default to make an autoincrementing column.

Old fashioned way (which doesn't work well with ruby):
create sequence test_id_seq;
create table test (id int primary key default nextval('test_id_seq'),
info text);

Easy method, which should work with ruby-pg:

create table test (id serial primary key, info text);