樞軸

Question

我需要從中選擇樞軸值來自於下面的支點列的名稱列選擇名稱...

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，如果一個值被選擇成瓦爾斯列，但實際上是從a3開始，那麼我需要將a3選入該記錄中的另一列。所以......

Vals | AColName 
    235.53  a3 
    48.54  a3 
    93.49  a1 

Answer 1

只是用數列中選擇如下：

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