MYSQL sum（）返回双分数

Question

我正在使用以下查询来生成排行榜，但由于某种原因它将分数返回为值的两倍。

SELECT p.user_id, u.first, SUM(points) AS score FROM points AS p LEFT 
JOIN users AS u ON p.user_id = u.fb_id WHERE p.action_time > 
'1492732800' GROUP BY p.user_id ORDER BY points DESC LIMIT 10 

什么可能导致这种情况发生？

感谢

Answer 1

一个解决办法是在一个单独的子查询聚集点，并加入到：

SELECT t1.fb_id, t1.first, t2.score 
FROM users t1 
INNER JOIN 
(
    SELECT user_id, SUM(points) AS score 
    FROM points 
    WHERE action_time > '1492732800' 
    GROUP BY user_id 
) t2 
    ON t2.user_id = t1.fb_id