SQL Server CASE函數僅返回字符串中的第一個值

Question

我正在使用CASE命令將子字符串查詢結果從一個數字更改爲名稱。

事情似乎很好，但我很難找出爲什麼結果只顯示字符串的第一個值。

Declare @OverrideON INT, @OverrideOFF INT 
SET @OverrideON = 1 SET @OverrideOFF = 0 

SELECT LonDeviceName, 
CASE WHEN SUBSTRING (PointValue,65,1) = @OverrideON THEN 'Fan In Override' 
     WHEN SUBSTRING (PointValue,67,1) = @OverrideON THEN 'HW In Override'  
     WHEN SUBSTRING (PointValue,69,1) = @OverrideON THEN 'CHW In Override' 
     WHEN SUBSTRING (PointValue,71,1) = @OverrideON THEN 'OAD In Override' 
     WHEN SUBSTRING (PointValue,73,1) = @OverrideON THEN 'VFD In Override' 
     WHEN SUBSTRING (PointValue,65,1) = @OverrideOFF THEN 'Fan Normal' 
     WHEN SUBSTRING (PointValue,67,1) = @OverrideOFF THEN 'HW Normal'  
     WHEN SUBSTRING (PointValue,69,1) = @OverrideOFF THEN 'CHW Normal' 
     WHEN SUBSTRING (PointValue,71,1) = @OverrideOFF THEN 'OAD Normal' 
     WHEN SUBSTRING (PointValue,73,1) = @OverrideOFF THEN 'VFD Normal' 
     ELSE '**StringError**' 
END as 'Manual Overrides' 
FROM dbo.Points 
WHERE LogicName like '%override%' 

當代碼運行它創建標題Manual Overrides列這是正確的，在該列中它顯示的字符串中的第一個值。但是，字符串中其他四個值的結果在哪裏。任何援助或想法將不勝感激。

謝謝。

Answer 1

怎麼是這樣的：

SELECT LonDeviceName, 
    CASE WHEN SUBSTRING (PointValue,65,1) = @OverrideON THEN 'In Override' 
      WHEN SUBSTRING (PointValue,65,1) = @OverrideOFF THEN 'Normal' 
      ELSE '**StringError**' 
    END as 'Fan', 
    CASE WHEN SUBSTRING (PointValue,67,1) = @OverrideON THEN 'In Override' 
      WHEN SUBSTRING (PointValue,67,1) = @OverrideOFF THEN 'Normal' 
      ELSE '**StringError**' 
    END as 'HW', 
    CASE WHEN SUBSTRING (PointValue,69,1) = @OverrideON THEN 'In Override' 
      WHEN SUBSTRING (PointValue,69,1) = @OverrideOFF THEN 'Normal' 
      ELSE '**StringError**' 
    END as 'CHW', 
    CASE WHEN SUBSTRING (PointValue,71,1) = @OverrideON THEN 'In Override' 
      WHEN SUBSTRING (PointValue,71,1) = @OverrideOFF THEN 'Normal' 
      ELSE '**StringError**' 
    END as 'OAD', 
    CASE WHEN SUBSTRING (PointValue,73,1) = @OverrideON THEN 'In Override' 
      WHEN SUBSTRING (PointValue,73,1) = @OverrideOFF THEN 'Normal' 
      ELSE '**StringError**' 
    END as 'VFD' 
FROM dbo.Points 
WHERE LogicName like '%override%' 

Answer 2

你是否真的需要這些笨重的變量來表示1和0？真？無論如何，真的在猜測你想要在這裏輸出什麼。也許這樣的：

SELECT LonDeviceName, [Manual Overrides] = '' 
    + 'Fan ' + CASE SUBSTRING (PointValue,65,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
    + ',HW ' + CASE SUBSTRING (PointValue,67,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
    + ',CHW ' + CASE SUBSTRING (PointValue,69,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
    + ',OAD ' + CASE SUBSTRING (PointValue,71,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
    + ',VFD ' + CASE SUBSTRING (PointValue,73,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
FROM dbo.Points 
WHERE LogicName LIKE '%override%'; 

或者，也許你只是想看看實際上是在覆蓋的值：也許你想單獨列畢竟

SELECT LonDeviceName, [Manual Overrides] = '' 
    + 'Fan ' + CASE SUBSTRING (PointValue,65,1) 
       WHEN '1' THEN 'In Override' ELSE '' END 
    + ',HW ' + CASE SUBSTRING (PointValue,67,1) 
       WHEN '1' THEN 'In Override' ELSE '' END 
    + ',CHW ' + CASE SUBSTRING (PointValue,69,1) 
       WHEN '1' THEN 'In Override' ELSE '' END 
    + ',OAD ' + CASE SUBSTRING (PointValue,71,1) 
       WHEN '1' THEN 'In Override' ELSE '' END 
    + ',VFD ' + CASE SUBSTRING (PointValue,73,1) 
       WHEN '1' THEN 'In Override' ELSE '' END 
FROM dbo.Points 
WHERE LogicName LIKE '%override%'; 

或者：

SELECT LonDeviceName, 
    + [Fan] = CASE SUBSTRING (PointValue,65,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
    + [HW] = CASE SUBSTRING (PointValue,67,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
    + [CHW] = CASE SUBSTRING (PointValue,69,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
    + [OAD] = CASE SUBSTRING (PointValue,71,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
    + [VFD] = CASE SUBSTRING (PointValue,73,1) 
       WHEN '1' THEN 'In Override' ELSE 'Normal' END 
FROM dbo.Points 
WHERE LogicName LIKE '%override%'; 

也許完全不同的東西。如果我們無法看到源數據或您想要的結果，那麼填寫您寫入的查詢與您想要的結果之間的差距是很困難的。