Rails的ActiveRecord的:加入与LEFT JOIN,而不是INNER JOIN [英] Rails ActiveRecord :joins with LEFT JOIN instead of INNER JOIN
本文介绍了Rails的ActiveRecord的:加入与LEFT JOIN,而不是INNER JOIN的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有这个code
User.find(:all, :limit => 10, :joins => :user_points,
:select => "users.*, count(user_points.id)", :group =>
"user_points.user_id")
这会产生以下SQL
which generates following sql
SELECT users.*, count(user_points.id)
FROM `users`
INNER JOIN `user_points`
ON user_points.user_id = users.id
GROUP BY user_points.user_id
LIMIT 10
是有可能使LEFT JOIN,而不是INNER JOIN的其他方式比 User.find_by_sql
和manualy输入查询?
is it possible to make LEFT JOIN instead of INNER JOIN other way than User.find_by_sql
and manualy typing the query?
推荐答案
您可以试试这个
User.find(:all, limit: 10,
joins: "LEFT JOIN `user_points` ON user_points.user_id = users.id" ,
select: "users.*, count(user_points.id)",
group: "user_points.user_id")
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