Another option is to set the default value of the field to the nextval,
such as for mytable primary key field
nextval(('public.users_user_id_seq'::text)::regclass). Then, when you
write your SQL
INSERT INTO mytable VALUES(default). I do it this way and find it a
little cleaner. If you want to access the users_user_id_seq value
within the same transaction, then after the insert into mytable you can
use currval.
Michael Schmidt