mysql - MYSQL SUM 双倍结果

Question

我有以下 SQL 但SUM返回意外值的..我不知道如何纠正它。

SQL：

SELECT 
    SUM(logs.amount*ei_relationships.itemprice) as spend, 
    SUM(log_users.amount) as recharged, 
    logs.cardid, 
    count(log_users.amount) as recharges 
FROM log_users
INNER JOIN logs ON logs.cardid = log_users.cardid
INNER JOIN ei_relationships ON ei_relationships.id = logs.ei_relationship_id
WHERE ei_relationships.event_id = 2 
GROUP BY logs.cardid 
ORDER BY recharged DESC

Aei_relationship有很多日志，也有很多log_users. 我尝试了不同的东西，但无法弄清楚。