mysql - mysql sum 在三个表上使用左连接

Question

我们有以下表格...

users
id, username password email

user_clubs
id, user_id, club_name

sales
id, club_id, amount, admin_fees, dnt

我们正在尝试将 admin_fees 的总和作为 user_id（例如 5）的未完成，我们尝试遵循...

SELECT u.id, count(c.id), SUM(s.admin_fees) as total_admin_fees 
FROM users u
LEFT JOIN user_clubs c ON c.user_id = u.id
LEFT JOIN sales s ON s.club_id = c.id
WHERE u.id = 5
GROUP BY u.id;

仅返回第一行的结果，这是不正确的，请帮助解决。

这是要测试的sql fiddle 。

谢谢

Answer 1

试试这个，user_id = 5因为有两个俱乐部 ID，数量为 2.5，所以总数应该是7

SELECT u.id, COUNT(c.id), SUM(s.admin_fees) AS total_admin_fees 
FROM users u
LEFT JOIN user_clubs c ON c.user_id = u.id
LEFT JOIN sales s ON s.club_id = c.id
WHERE u.id = 5
GROUP BY s.club_id;

对于所有用户，您都可以这样做

SELECT u.id, COUNT(c.id), SUM(s.admin_fees) AS total_admin_fees 
FROM users u
LEFT JOIN user_clubs c ON c.user_id = u.id
LEFT JOIN sales s ON s.club_id = c.id

GROUP BY u.`id`;

小提琴