Mysql SELECT和COUNT WHERE

Question

我有两个表（让我们称之为案例和用户）结构如下：案例

ID|status      |user_id
__|____________|_______  
1 |Open        |6
2 |Closed      |9
3 |Incomplete  |9

用户：

ID| 
__|_____
 6|
 9|

我想选择id的计数以及每个状态字段的计数。

目前我尝试过：

SELECT COUNT(c.id), COUNT(
(SELECT status from cases where status = 'Open')),
COUNT(
(SELECT status from cases where status = 'Closed')),
COUNT(
(SELECT status from cases where status = 'Incomplete'))
FROM cases as c
JOIN users as u on u.id = c.user_id

我收到错误的查询返回多行。

这就是我想要实现的目标

ID| Open | Closed | Incomplete |user_id
__|______|________|____________|__________
 2|0     |1       |1           |9

RECAP：每个用户ID的计数，用于计算ID的数量和每个状态的计数。

Answer 1

您可以使用sum

尝试此操作

SELECT COUNT(c.id), 
SUM(c.status = 'Open') Open ,
SUM(c.status = 'Closed') Closed ,
SUM(c.status = 'Incomplete') Incomplete,
u.id user_id
FROM cases as c
JOIN users as u on u.id = c.user_id
GROUP BY u.id