mysql 不同条件count ,多条件count()

 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′

 

转载于:https://www.cnblogs.com/yuzhould/p/10424690.html

    原文作者:weixin_34221073
    原文地址: https://blog.csdn.net/weixin_34221073/article/details/93781346
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