SQL WHERE子句的情況下與像

Question

塊引用

DECLARE @Symbol nvarchar(50); 
DECLARE @EnDate1 Datetime; 
DECLARE @StDate1 Datetime; 
SET @Symbol = 'RIM12f' 
SET @EnDate1 = '05/08/2012 9:00' 
SET @StDate1 = '05/07/2012 12 : 00' 
SELECT * 
FROM Siri 
WHERE (DATEADD(D, 0, DATEDIFF(D, 0, Date)) BETWEEN @StDate1 AND @EnDate1) 
    AND CASE Symbol = WHEN @Symbol = 'ALL' 
        THEN Symbol 
        ELSE Symbol LIKE LEFT(@Symbol, len(@Symbol) - 3) + '%' 
     END 

它不工作方式相同，但 它與其他@Symbol 但我需要一個像LEFT（@Symbol，LEN（@Symbol）所有符號 - 3）+ '％' 如果@Symbol比所有

Answer 1

其他修改你的CASE表達式：

Symbol LIKE CASE @Symbol WHEN 'ALL' 
        THEN Symbol 
        ELSE LEFT(@Symbol, len(@Symbol) - 3) + '%' 

Answer 2

DECLARE @Symbol nvarchar(50); 
DECLARE @LikeSymbol nvarchar(50); 

DECLARE @EnDate1 Datetime; 
DECLARE @StDate1 Datetime; 
SET @Symbol = 'RIM12f' 
SET @EnDate1 = '05/08/2012 9:00' 
SET @StDate1 = '05/07/2012 12 : 00' 
SET @LikeSymbol = LEFT(@Symbol, length(@Symbol) - 3) + '%' 
SELECT * 
FROM Siri 
WHERE (DATEADD(D, 0, DATEDIFF(D, 0, Date)) BETWEEN @StDate1 AND @EnDate1) 
AND (
(@Symbol = 'All') 
OR 
(Symbol Like @LikeSymbol) 
) 

猜測明朗

Answer 3

看到作爲查詢的意圖是遠遠不能在CASE都=和嵌套LIKE ..你可以像使用或使用OR和AND結構..（如建議@Tony霍普金森）

這裏被修改的情況下：

Symbol like CASE WHEN @Symbol = 'ALL' 
        THEN Symbol 
        ELSE LEFT(@Symbol, len(@Symbol) - 3) + '%' 
END