数据排序存储过程

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go

ALTER PROCEDURE [dbo].[SetTaskPosition]
 @TaskID uniqueidentifier,
 @Position int
AS

 DECLARE @ListID uniqueidentifier
 DECLARE @OldPosition int
 
 SELECT
  @ListID = ListID, @OldPosition = ListOrder
 FROM
  Tasks
 WHERE TaskID = @TaskID
 
 IF @Position < @OldPosition
 BEGIN
 
  UPDATE Tasks
  SET
   ListOrder = ListOrder + 1
  WHERE
   ListID = @ListID AND ListOrder >= @Position AND ListOrder < @OldPosition
 
  UPDATE TOP(1) Tasks
  SET
   ListOrder = @Position
  WHERE
   TaskID = @TaskID
 
 END
 ELSE IF @Position > @OldPosition
 BEGIN

  UPDATE Tasks
  SET
   ListOrder = ListOrder - 1
  WHERE
   ListID = @ListID AND ListOrder > @OldPosition AND ListOrder <= @Position
  
  UPDATE TOP(1) Tasks
  SET
   ListOrder = @Position
  WHERE
   TaskID = @TaskID

 END