枢轴

Question

我需要从中选择枢轴值来自于下面的支点列的名称列选择名称...

SELECT DISTINCT 
    filename, 
    vals 
FROM 
    (SELECT 
     filename, 
     a1, 
     a2, 
     a3 
    FROM 
     foo) p 
UNPIVOT 
    (vals FOR counts IN 
     (a1,a2,a3) 
) AS bar 

所以，如果一个值被选择成瓦尔斯列，但实际上是从a3开始，那么我需要将a3选入该记录中的另一列。所以......

Vals | AColName 
    235.53  a3 
    48.54  a3 
    93.49  a1 

Answer 1

只是用数列中选择如下：

SELECT DISTINCT 
    filename, 
    vals,counts 
FROM 
    (SELECT 
     filename, 
     a1, 
     a2, 
     a3 
    FROM 
     foo) p 
UNPIVOT 
    (vals FOR counts IN 
     (a1,a2,a3) 
) AS bar