SQL query

having.sql

Tables:
 -users
   -timestamps
 -enterprises
 -enterprise_users
   -user_id
   -enterprise_id

Goal:
Trying to find a query for all users for a given enterprise, but only for users for ONLY that enterprise. In otherwords, if a user is part of more than one enterprise (can assume simply more than one enterprise_users record for that user_id), then I *don't* want that returned.

Query so far:
SELECT COUNT(*) AS count_all, enterprise_users.enterprise_id AS enterprise_users_enterprise_id FROM `users` INNER JOIN `enterprise_users` ON `enterprise_users`.`user_id` = `users`.`id` WHERE (users.created_at > date('2012-02-01') AND users.created_at < date('2012-03-01') AND enterprise_users.enterprise_id = 1) GROUP BY enterprise_users.enterprise_id HAVING count(enterprise_users.enterprise_id) < 2

But this returns zero results. I know the results for both "this enterprise" and "ONLY this enterprise"

with
alluserlist as (select user_id from enterprise_users where enterprise_id = 1),
onlyuserlist as (select user_id from alluserlist, enterprise_users
where alluserlist.user_id = enterprise_users.user_id
group by user_id having count() < 2)
select count()
from onlyuserlist