扩展性很好的一个分页存储过程

这是经常用的一个分页存储过程  希望大家指点不足

USE [a6756475746]
GO
/****** Object:  StoredProcedure [dbo].[tbl_order_SearchWhereAndPage]    Script Date: 11/01/2011 09:37:39 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[tbl_order_SearchWhereAndPage]
	@AllCount 	int OUTPUT,
	@PageIndex 	int,
	@PageSize 	int ,
	@minDate   datetime,
	@maxDate   datetime
AS
begin
	DECLARE @PageLower int 
     set @PageLower=@PageSize * @PageIndex 
	DECLARE @PageUpper int 
     set @PageUpper= @PageLower + @PageSize - 1

	DECLARE @SearchSQL nvarchar(4000)
     set @SearchSQL='SELECT * ,( ROW_NUMBER() OVER (ORDER BY [ID] DESC) -1 ) AS RowNumber FROM tbl_order WHERE  (1=1) '
	DECLARE @SearchSQLCount nvarchar(4000)
     set @SearchSQLCount='SELECT @count=Count(*) FROM tbl_order WHERE (1=1) '
	declare @Result   [varchar](5000)
     set @Result=''
	
	if @minDate>convert(datetime,'1900-1-2')
	begin
		set @Result=@Result+' and oDeliveryDate >= '''+convert(varchar(20),@minDate)+'''' 
	end 
	if @maxDate > convert(datetime,'1900-1-2')
	begin
		set @Result=@Result+' and oDeliveryDate <= '''+convert(varchar(20),dateadd(dd,1,@maxDate))+'''' 
	end 
	set @SearchSQLCount=@SearchSQLCount+@Result
	set @SearchSQL=@SearchSQL+@Result

	SET @SearchSQL = 'WITH t AS (' + @SearchSQL +' )
	SELECT * FROM  t
	WHERE [RowNumber] BETWEEN '+ convert(varchar(50),@PageLower) +'  AND '+ convert(varchar(50),@PageUpper) + '
	ORDER BY RowNumber '

	exec (@SearchSQL)

	exec sp_executesql @SearchSQLCount ,N'@count as int out' ,@AllCount out 

	print @SearchSQL
	
print @AllCount
end
exec (@Result)