SQL自定义订单编号

USE [EduExam]
GO
/****** Object:  StoredProcedure [dbo].[Pro_DingDan]    Script Date: 06/30/2013 00:15:49 ******/
SET ANSI_NULLS OFF
GO
SET QUOTED_IDENTIFIER OFF
GO
ALTER PROC [dbo].[Pro_DingDan]
@QianZhui varchar(20)='DDR'
AS
Declare @Res varchar(20),@Max int,@CurrentDate varchar(20)
set @Res=''
set @Max=0

--获取当前日期字符串
select @CurrentDate=CAST(YEAR(GETDATE()) as varchar)+  --年
                    CAST(MONTH(GETDATE()) as varchar)+ --月
                    CAST(DAY(GETDATE()) as varchar)    --天
select @Max=MAX(Cast(Right(订单编号,8)as int)) 
from [dbo].[Sys_DingDan]

--新建的表可能上面查询为空

if(ISNULL(@Max,0)>0)
 Begin
   select @Res=@QianZhui+@CurrentDate+Right('00000000'+cast(@Max + 1 as varchar),8)
 End
else
 Begin
   Select @Res = @QianZhui+@CurrentDate + '00000001' 
 end
   insert into Sys_DingDan select @Res,GETDATE()
   select * from  Sys_DingDan
 go
 exec Pro_DingDan