create table abc(A int,B int)

Select A,count(B) as total from ABC group by A

Select A,count(B) as total1 from ABC where B > 30 group by A

Select A,count(B) as totlal2 from ABC where B > 20 group by A

如何合并这三个查询？

得到一个查询结果：

A,total,total1,total2

答：

Select A,

count(B) as total,

sum(case when B > 30 then 1 else 0 end) as total1,

sum(case when B > 20 then 1 else 0 end) as total2

from ABC group by A

自己的例子

select  count(1)  from origin_crx_data  where create_time like '2019-02-23%' and source='12345'

select  count(1)  from origin_crx_data  where active_time like '2019-02-23%' and source='12345'

合并为一条sql

SELECT

sum(case when create_time like '2019-02-23%' then 1 else 0 end) as inst_count,

sum(case when active_time like '2019-02-23%' then 1 else 0 end) as active_count

FROM  origin_crx_data   where source='12345'

原文链接：https://blog.csdn.net/weixin_35952362/article/details/113127237