SQL查詢：如果x = 1，則選擇全部，然後y <z否則如果x = 2，那麼y <w

Question

我想選擇所有列，但是如果fuel = 1，那麼開始日期>'oct oct 2013'else else if fuel = 0開始日期>'9月1日'。

使用SQL Server 2005

我想這個..

SELECT * FROM EntitlementEpisode 
WHERE 
    IF EnFuel = 1 
     THEN 
      IF 
       BEGIN 
        [EnEpisodeStart] > 
        (SELECT TOP 1 [BeYearStart] 
        FROM [BenefitYear] ORDER BY [BeId] desc) 
       END 
      ELSE IF EnFuel = 0 
     THEN 
      IF 
       BEGIN 
         [EnEpisodeStart] > 
         CONVERT(VARCHAR(30), '1 OCT' + YEAR(GETDATE())) 
      END 

這是要去了解它的正確方法？

Answer 1

使用二元運算符的強度...！

SELECT * 
FROM EntitlementEpisode 
WHERE 
    (EnFuel=1 AND EnEpisodeStart] > 
       (SELECT TOP 1 [BeYearStart] 
       FROM [BenefitYear] ORDER BY [BeId] desc)) 

    OR 

    (EnFuel=0 AND [EnEpisodeStart] > 
        CONVERT(VARCHAR(30), '1 OCT' + YEAR(GETDATE()))) 

Answer 2

如何像

SELECT * 
FROM EntitlementEpisode 
WHERE (EnFuel = 1 AND [EnEpisodeStart] > (SELECT TOP 1 [BeYearStart] FROM [BenefitYear] ORDER BY [BeId] desc) 
OR  (EnFuel = 0 AND [EnEpisodeStart] > CONVERT(VARCHAR(30), '1 OCT' + YEAR(GETDATE())))