最近有一個朋友問我一個關于給查詢操作強制上X鎖卻不阻塞的問題。該查詢寫在一個存儲過程中，代碼如代碼1所示：

   1: create PROC [dbo].[GetCityOrders]

   2:     @city NVARCHAR(10) ,

   3:     @num INT

   4: AS

   5:     SET NOCOUNT ON

   6:  

   7:     BEGIN TRY

   8:  

   9:         BEGIN TRAN

  10:  

  11:         SELECT TOP ( @num )

  12:                 id ,

  13:                 number ,

  14:                 price ,

  15:                 mid ,

  16:                 @city city

  17:         INTO    #cityorders

  18:         FROM    cmcc WITH ( XLOCK )