mysql - Mysql SUM 基于另一个计算的归档条件

Question

共有三个表用户、列表、详细信息。这是我的表结构和数据示例

userid username   |  list_id  list_val  user_id  |   detail_id   list_id   multipler
1      user1      |     1       500        1     |      1           1         3
2      user2      |     2       300        1     |      2           1         2
3      user3      |     3       600        1     |      3           2         1
                        4       100        2            4           2         1
                                                        5           3         4

SELECT
users.username,
SUM(lists.lists_var),
FROM
users
INNER JOIN lists ON users.userid = lists.user_id
GROUP BY
users.username
HAVING
(SELECT (exp(sum(log(COALESCE(details.multipler, 1))))) FROM details WHERE
details.list_id = lists.list_id) > 3

这个查询给了我结果

user1 - 1400

但我想要一些 IF multipler_total > 3 THEN SUM(list_val) 所以结果必须是：

user1 - 1100

Answer 1

试试这个：

SELECT
users.username,
SUM(lists.lists_var),
FROM
users
INNER JOIN lists ON users.userid = lists.user_id
INNER JOIN (SELECT list_id, SUM(multiplier) mult_total FROM details GROUP BY list_id) d
ON d.list_id = lists.list_id and d.mult_total > 3
GROUP BY
users.username