Mysql 行值作为具有计数 (*) 的列

Question

我有一个具有以下结构的 table，我正在尝试将行值用作列，并将它们的值用作出现次数。

|  date     |order|status|
-----+-----+----------------
| 2018-05-22|    1|  closed|
| 2018-05-22|    2|  closed|
| 2018-05-22|    3|  closed|
| 2018-05-22|    4|  open  | 
| 2018-05-22|    4|  open  |

输出：

|  date     |closed|open|
-----+-----+----------------
| 2018-05-22|   3  |  2|

当我使用以下查询获取计数 (*) 值时出现错误..."invalid use of group function"

select date,
  max(case when `status` ='closed' then count(*) end) closed,
  max(case when `status` = 'open' then count(*) end) open
from orders where date ='2018-05-22' group by date,status

感谢帮助修复它...

Answer 1

下面的怎么样？

select
  date,
  sum(case when `status` ='closed' then 1 else 0 end) closed,
  sum(case when `status` = 'open' then 1 else 0 end) open
from orders where date ='2018-05-22' group by date

Mysql 行值作为具有计数 (*) 的列

Mysql row values as columns with count(*)

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