Question

我正在做一个项目，并陷入了困境。问题是我有以下两个表：

1. users :
+----+------+
| id | name |
+----+------+
|  1 | ABC  |
|  2 | XYZ  |
|  3 | JKL  |
+----+------+

2. user_mistakes :
+----+---------+-------------+--------+
| id | user_id |   mistake   | status |
+----+---------+-------------+--------+
|  1 |       1 | Lorem ipsum |      1 |
|  2 |       1 | Lorem ipsum |      1 |
|  3 |       2 | Lorem ipsum |      0 |
|  4 |       2 | Lorem ipsum |      1 |
+----+---------+-------------+--------+

user_mistakes。status在 0 =待审核和1 =已批准

根据上述users和user_mistakes表数据，我希望每个用户的未决和批准状态计数如下：

+---------+------+------------------+-------------------+
| user_id | name | pending_mistakes | approved_mistakes |
+---------+------+------------------+-------------------+
|       1 | ABC  |                0 |                 2 |
|       2 | XYZ  |                1 |                 1 |
|       3 | JKL  |                0 |                 0 |
+---------+------+------------------+-------------------+

有什么方法可以通过单个查询实现？

谢谢

Answer 1

您可以尝试以下代码：

SELECT
    users.id,users.name,
    SUM(IF(mistakes.status=1, 1, 0)) AS approved_mistakes,
    SUM(IF(mistakes.status=0, 1, 0)) AS pending_mistakes
FROM users
LEFT JOIN mistakes ON mistakes.user_id = users.id
GROUP BY mistakes.user_id

让我知道您是否遇到任何问题

Answer 2

选择待处理的错误，并根据未处理的错误从user_mistakes组中计数（待处理的错误）

MySQL：获取每个用户的状态（待批准）

2 个答案: