ruby-on-rails - Rails ActiveRecord :joins with LEFT JOIN instead of INNER JOIN

Question

我有这个代码

User.find(:all, :limit => 10, :joins => :user_points,
                :select => "users.*, count(user_points.id)", :group =>
                "user_points.user_id")

生成以下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

除了 User.find_by_sql 并手动输入查询之外，是否可以使用 LEFT JOIN 而不是 INNER JOIN？

Answer 1

你可以试试这个

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")