SQL服务器数再行

Question

怎么可能会导致我这样？ 在我看来，我可以查询=>

select id, count(no1, no2, no3) where no1='B',no2='B',no3='B' 

非常感谢。

Answer 1

使用Case When陈述与Count骨料。最后，集团他们id：

Select id, 
     count(case when no1='B' then 1 END) + 
     count(case when no2='B' then 1 END) + 
     count(case when no3='B' then 1 END) AS count_all 
From yourtable 
Group by id 

Answer 2

使用Case Statement

select id, 
     case when no1='B' then 1 else 0 END + 
     case when no2='B' then 1 else 0 END + 
     case when no3='B' then 1 else 0 END As Count_All 
From yourtable