如何將字符串值分配給SQL視圖中的數值

Question

本質上，我有一個測試用例場景，我需要將計算的百分比分配給文本值。例如。 < 80 =「B」 < 70 =「C」

這裏是

Select *... 
    100 * COUNT(CASE TurnedIn WHEN 1 THEN 1 ELSE NULL END) 
          /COUNT(TurnedIn) AS Percentage, 
From Table1 
When ... 

我曾嘗試包裹基於在切換作業的數量的拉動值到百分之我的代碼的相關部分。這種情況下，如

Case when (100 * COUNT(CASE TurnedIn WHEN 1 THEN 1 ELSE NULL END) 
          /COUNT(TurnedIn)) <= 80 Then 'B' As LetterGrade 

但到目前爲止沒有運氣。

Answer 1

寫爲：

Select *, --name all columns you want 
      case when Percentage < 80 then 'B' 
       when Percentage < 70 then 'C' 
       else 'Add the grade which should be default when above 2 
         case conditions are not met' 
      end as LetterGrade 
    from (  
    Select *, 
     100 * COUNT(CASE TurnedIn WHEN 1 THEN 1 ELSE NULL END) 
           /COUNT(TurnedIn) AS Percentage 
    From Table1 
    When ..) T 

Answer 2

你可以試試這個，

With CTE as 
(

Select (100 * COUNT(CASE TurnedIn WHEN 1 THEN 1 ELSE NULL END) 
        /COUNT(TurnedIn))  as Percentage 

    from myTable   
)   
select Case When Percentage <70 
      Then 'C' 
      When Percentage <80 
      Then 'B' 
      Else 'A' 
     End 
from CTE