如何在多个条件下求和并显示多列

Question

我有一个这样的表，现在我需要获取所有数据GROUP BY tpi

+---------------------+---------+----------------+
| trxDate             | trxType | tpi            |
+---------------------+---------+----------------+
| 2018-06-28 00:00:00 | Sent    | SI0005         |
| 2018-07-02 00:00:00 | Sent    | SI0005         |
| 2018-07-04 00:00:00 | Sent    | SI0005         |
| 2018-05-25 00:00:00 | Open    | SI0007         |
| 2018-06-26 00:00:00 | Open    | SI0007         |
| 2018-05-25 00:00:00 | Sent    | SI0007         |
| 2018-06-23 00:00:00 | Sent    | SI0007         |
+---------------------+---------+----------------+

我需要记录以总计打开并发送

+---------------------+---------+----------------+
| tpi                 | open    | sent           |
+---------------------+---------+----------------+
|  SI0005             | 0       | 3              |
|  SI0007             | 2       | 2              |   
+---------------------+---------+----------------+

我尝试了一些子查询，但是没有得到想要的响应

SELECT  tblcount.tpi, tblcount.qType, count(tblcount.id) total FROM (SELECT id, tpi, 'Open' qType FROM `tbl`WHERE trxType = 'Open' UNION SELECT id, tpi, 'Sent' qType FROM `tbl` WHERE trxType = 'Sent') tblcount GROUP BY  tblcount.third_party_id, tblcount.qType

Answer 1

您可以进行有条件的聚合：

select tpi,
       sum(trxType = 'Open') as trxType_open, 
       sum(trxType = 'Sent') as trxType_Sent
from tbl t
group by tpi;

Answer 2

只需使用条件聚合：

select tpi,
       sum( (trx_type = 'open') ) as num_open,
       sum( (trx_type = 'sent') ) as num_sent
from tbl
group by tpi;

这使用MySQL扩展，该扩展将布尔表达式视为整数上下文中的整数，其中“ 1”表示true，“ 0”表示false。