TopSystem - Swap Field Value Form 2Record

USE [MHQST_GameDB]
GO
/****** Object:  StoredProcedure [dbo].[Arena_Get_Rival]    Script Date: 10/16/2012 20:18:58 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:        <Author,,Name>
-- Create date: <Create Date,,>
-- Description:    <Description,,>
-- =============================================
--BM_Add 12.10.10-16.29
ALTER PROCEDURE [dbo].[Arena_Get_Rival]
            @Challenge    int    
            ,@Rival        int    
AS
BEGIN
    UPDATE T_Player   

   SET ArenaTop = (CASE  

                   WHEN RoleID = @Challenge THEN  

                    (SELECT ArenaTop FROM T_Player WHERE RoleID = @Rival)   

                   WHEN RoleID = @Rival THEN  

                    (SELECT ArenaTop FROM T_Player WHERE RoleID = @Challenge)   

                 END)   

  WHERE RoleID = @Challenge OR RoleID = @Rival;  
    
END