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?