SQL将重复行计为单个

Question

我有桌子

ID     State        District        StationCode        Status
---------------------------------------------------------------
 1    Gujarat       Banaskantha      12345               0 
 2    Gujarat       Banaskantha      12345               0
 3    M.P.          Bhopal           22315               1
 4    Gujarat       Banaskantha      12349               0
 5    Gujarat       Banaskantha      12345               1

我需要结果

State      District       Active       InActive
-----------------------------------------------
Gujarat     Banaskantha      2            1
M.P.        Bhopal           0            1

在这里,Active 和Inactive字段的总和Status基于域0或1

这意味着State古吉拉特邦,three有时出现0,但two重复的行StationCode - 12345.这意味着它将被视为One.

我有如下查询

select distinct 
    state,
    District,
    SUM(
        Case 
        when Status=0 then 1 
        else 0 end
        ) AS Active,
    SUM(
        Case 
            when Status=1 then 1 
            else 0 
        end
        ) AS InActive 
from 
    Station_Master 
group by state, District

但我无法将重复StationCode行计为单个.

我怎样才能做到这一点 ？

Answer 1

您可以唯一地过滤子查询中的行。尝试，

SELECT  DISTINCT state, district,
        SUM(CASE WHEN status = 0 THEN 1 ELSE 0 END) Active,
        SUM(CASE WHEN status = 1 THEN 1 ELSE 0 END) InActive
FROM (
        SELECT DISTINCT state,  district, StationCode, status 
        FROM  Station_Master
    ) a
GROUP BY state, district

SQLFiddle 演示

Answer 2

我想这可能会解决你的问题。我不是 100% 确定语法，但如果您可以尝试一下并让我知道它是否不起作用，我可以尝试为您调整它。这个想法是使用 Group By 创建一个派生表，首先消除您不想要的重复项，然后外部查询与原始查询相同 - 只是在派生表上。

SELECT Distinct 
  X.State, 
  X.District, 
  SUM(Case when X.Status=0 then 1 else 0 end) AS Active,
  SUM(Case when X.Status=1 then 1 else 0 end) AS InActive
FROM 
  (Select State, District, StationCode, Status
   From Station_Master 
   Group By State,District, StationCode, Status) as X
GROUP BY X.State, X.District