Question

我想对由列名确定的列求和，该列将作为诸如HAVING SUM（@variable）之类的变量传递进来

例如，我想传递HR列并求和，尽管我可能想用不同的列求和

DECLARE @column varchar(20) = 'HR'

SELECT 
    Batting.playerID,
    SUM(G)      as G,
    SUM(AB)     as AB,
    SUM(R)      as R,
    SUM(H)      as H,
    SUM([2B])   as '2B',
    SUM([3B])   as '3B',
    SUM(HR)     as HR,
    SUM(RBI)    as RBI,
    SUM(SB)     as SB,
    SUM(BB)     as BB,
    SUM(HBP)    as HBP

FROM Batting 

GROUP BY playerID
HAVING SUM(@column) > 600

Answer 1

这会将所选列返回为Val。不能更改列的名称，但可以得到结果：

DECLARE @column varchar(20) = 'HR'

select * from (
SELECT 
    Batting.playerID,
    sum(
        case 
            when @column='G' then G
            when @column='AB' then AB
            when @column='R' then R
            ... etc...
    end) as val
FROM Batting 
GROUP BY playerID
) q where val > 600

使用变量作为HAVING SUM（@variable）中使用的列名

1 个答案: