执行一个字符串

Question

DECLARE @userName varchar(30)
SET @userName='KaowuTest'
DECLARE @sqlget varchar(1000)
SET @sqlget='
SELECT [RequestListID]
      ,[RequestListNo]
      ,[RequestListName]
      ,[TaskTypeCode]
      ,[ProjectID]
      ,[IsFinance]
      ,[TaskBackground]
      ,[Taskdescription]
      ,[IsOpen]
      ,[CreateDate]
      ,[Creator]
      ,[CreatorName]
      ,[Re]    
FROM  dbo.Task_OtherRequestList  
where Creator='''+@userName+'''    
union    
SELECT [RequestListID]
      ,[RequestListNo]
      ,[RequestListName]
      ,[TaskTypeCode]
      ,[ProjectID]
      ,[IsFinance]
      ,[TaskBackground]
      ,[Taskdescription]
      ,[IsOpen]
      ,[CreateDate]
      ,[Creator]
      ,[CreatorName]
      ,[Re]    
 FROM dbo.Task_RequestList   where Creator='''+@userName+''''
exec @sqlget出错 不是有效的标识符但是我用print打出sqlget再运行就没错