我如何在Rails中找到左联接

我有这个

User.joins(:notifications).joins(:company_users).joins(:role_users).where("notifications.id = ? AND role_users.role_id != '1' AND (company_users.company_id = ? OR users.company_id = ?)", notification.id, p.company_id, p.company_id)

=> []

产生此sql

SELECT `users`.* FROM `users` 
INNER JOIN `subscriptions` ON `users`.`id` = `subscriptions`.`user_id` 
INNER JOIN `notifications` ON `notifications`.`id` = `subscriptions`.`notification_id` 
INNER JOIN `company_users` ON `company_users`.`user_id` = `users`.`id` 
INNER JOIN `role_users` ON `role_users`.`user_id` = `users`.`id` 
WHERE (notifications.id = 1 
AND role_users.role_id != '1' 
AND (company_users.compcany_id = 67 OR users.company_id = 67))

问题是我需要在company_users上退出联接，并且不确定如何在Rails中实现该目标

the problem is I need to left join on company_users and not sure how to achieve that in rails

我知道我可以用find_by_sql做到这一点，因为我听说那并不是真的.....任何想法

I know I can do this with find_by_sql by i heard thats not really rails like....any ideas