Re: Function PostgreSQL 9.2

This is what I've done:

-- 1 - Creating the Sequence:

CREATE SEQUENCE users_code_seq
> INCREMENT 1
> MINVALUE 1
> MAXVALUE 9223372036854775807
> START 1000;
> CACHE 1;

-- 2 - Setting the DEFAULT

ALTER TABLE public.users ALTER COLUMN code SET DEFAULT
> NEXTVAL('users_code_seq');

-- 3 - Setting the column as NOT NULL;

>
> ALTER TABLE public.users ALTER COLUMN code SET NOT NULL;

-- 4 - Setting the trigger

CREATE TRIGGER public.update_code_column
> BEFORE UPDATE OR INSERT
> ON public.users
> FOR EACH ROW
> EXECUTE PROCEDURE public.users_code_seq;

-- 5 - Creating a CONSTRAINT UNIQUE

> ALTER TABLE public.users
> ADD CONSTRAINT uc_users_code UNIQUE("code");

Is that right?
Am I missing something?

Cheers
Lucas