具有计数和列查询的组合

Question

我有一个连接表与两列组合主键。 我想查询所有条目

columnA having count > 1 

和

columnB = value1 and value2 

我的查询到目前为止是这样的

select 
    columnA 
from tableA 
where columnB = 1 and 
columnA in (
     select 
      columnA 
     from tableA 
     group by columnA 
     having count(columnA) > 1) 

或

select 
     columnA 
    from tableA 
    where columnB = 2 and 
    columnA in (
      select 
       columnA 
      from tableA 
      group by columnA 
      having count(columnA) > 1) 

我如何可以查询

...columnB = 1 and columnB = 2 and columnA in (select .... 

Answer 1

select columnA 
from tableA 
where columnB in (1,2) 
group by columnA 
having count(distinct columnB) = 2 

有两个值1和2在columnB fullfills自动count(columnA) > 1

如果你想要么的columnB条件（columnB有2个值）或的columnA条件，那么做

select columnA 
from tableA 
group by columnA 
having count(*) > 1 
or count(distinct columnB) = 2 

或columnB必须1和2

select columnA 
from tableA 
group by columnA 
having count(*) > 1 
or 
( 
    sum(case when columnB = 1 then 1 else 0 end) > 0 and 
    sum(case when columnB = 2 then 1 else 0 end) > 0 
)