SQL：選定的日期超出範圍

Question

我有一個查詢，它返回行創建時的最新日期。日期爲「2010-02-03」

SELECT * FROM 
[LinkedServer].[Server].[Table] 
WHERE [TimeStamp]= (SELECT MAX(TimeStamp) 
FROM [LinkedServer].[Server].[Table] 
WHERE UserName IN 
(SELECT Tagname COLLATE DATABASE_DEFAULT FROM LocalServer.MyDatabase.dbo."Taglist" 
WHERE LOCATION = 'Europe' AND COUNTRY = 'England')) 

此查詢工作正常，但是我想插入一個IF ELSE語句，所以如果我選擇不同的日期，比MAX（時間戳）更大然後返回一個錯誤信息。我嘗試的方式如下：

IF MAX(TimeStamp) > '2011-02-15' 
BEGIN 

SELECT * FROM 
[LinkedServer].[Server].[Table] 
WHERE [TimeStamp]= (SELECT MAX(TimeStamp) 
FROM [LinkedServer].[Server].[Table] 
WHERE UserName IN 
(SELECT Tagname COLLATE DATABASE_DEFAULT FROM LocalServer.MyDatabase.dbo."Taglist" 
WHERE LOCATION = 'Europe' AND COUNTRY = 'England')) 

END 
ELSE 
PRINT 'Date out of range' 

不幸的是，這種方式查詢不起作用。關於我應該在哪裏更改代碼的任何建議？ 謝謝！

Answer 1

Declare @MaxTS datetime 

SELECT @MaxTS=MAX(TimeStamp) 
FROM [LinkedServer].[Server].[Table] 
WHERE UserName IN 
(SELECT Tagname COLLATE DATABASE_DEFAULT FROM LocalServer.MyDatabase.dbo."Taglist" 
WHERE LOCATION = 'Europe' AND COUNTRY = 'England') 

IF @MaxTS > '20110215' 
BEGIN 

SELECT * FROM 
[LinkedServer].[Server].[Table] 
WHERE [TimeStamp]= @MaxTS 

END 
ELSE 
PRINT 'Date out of range'