Question

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)

=＆GT; []

生成这个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上保持联接并且不确定如何在rails中实现它

我知道我可以通过find_by_sql来做到这一点，我听说这不是真正的轨道......任何想法

Answer 1

解决

User.joins(:notifications).joins("LEFT JOIN `company_users` ON `company_users`.`user_id` = `users`.`id`").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)

Answer 2

class User＆lt;的ActiveRecord ::基

 has_many :friends, :foreign_key=>"u_from",:class_name=>"Friend"

端

类朋友＆lt;的ActiveRecord ::基

 belongs_to :user

端

friends = user.friends.where（：u_req_status =＆gt; 2）.joins（“LEFT OUTER JOIN users ON users.u_id = friends.u_to”）。select（“friend_id，u_from，u_to，u_first_name，u_last_name， u_email，u_fbid，u_twtid，u_picture_url，u_quote“）

如何在rails中找到左连接

2 个答案: