Sql产生自动增长的编号

USE [DBName]
GO
/****** Object:  StoredProcedure [dbo].[sp_GetNo]    Script Date: 10/24/2013 19:26:44 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:  <Author, XiaoPan.Gong>
-- Create date: <Create Date, 2013-10-23>
-- Description: <Description, Upload Special Event Amout>
-- =============================================
 /* 第一
  CREATE TABLE [dbo].[T_Saler](
  [Id] [int] IDENTITY(1,1) NOT NULL,
  [SO_No] [nvarchar](50) NULL,
  [Name] [nvarchar](50) NULL,
  [Sale_Num] [int] NULL,
  [Remark] [nvarchar](max) NULL
 )
 --执行
 Declare @Get_No nvarchar(50)

 exec [dbo].[sp_GetNo] 'T_Saler','SO_No',10,8,'SN',@Get_No output

 print @Get_No
 
 SONO2013102400000001
 */
ALTER PROCEDURE [dbo].[sp_GetNo]
(
 @table_name nvarchar(50),--表名
 @field nvarchar(50),--字段名
 @left int,--左边截取的长度
 @right int,--右边截取的长度
 @split nvarchar(10),--编号其实字母或字符串
 @return_no nvarchar(50) output --返回的编号
)
AS
BEGIN
 Declare @sql nvarchar(MAX)
 Declare @rightnum int
 Declare @splitstr nvarchar(50)
 Declare @rightstr nvarchar(10)
 Declare @rightint int
 Declare @tbno nvarchar(50)
 
 Set @rightint=@right
 Set @rightstr=''
 
 while @rightint>0
 begin
 
  Set @rightstr=@rightstr+'0'
 
  Set @rightint=@rightint-1
 
 end
 
 Set @splitstr=@split+CONVERT(nvarchar,GETDATE(),112)
 
 
 Set @sql='select @rightnum=MAX(Convert(int,right(Convert(nvarchar,isnull( '+@field+',0)),'+Convert(nvarchar,@right)+'))) from '
     +@table_name+' where left( '+@field+','+Convert(nvarchar,@left)+')='+''''+@splitstr+''''

 
 EXEC SP_EXECUTESQL @sql, N'@rightnum int OUTPUT', @rightnum OUTPUT
 
 if @rightnum is null
 begin
  Set @rightnum=0
 end
 
 Declare @rightlen int
 Declare @rightlenght int
 
 Set @rightlen=LEN(Convert(nvarchar,@rightnum))

 Set @rightnum=@rightnum+1

 Set @rightlenght=LEN(Convert(nvarchar,@rightnum))
 
 if @rightlen=@rightlenght
  begin
   Set @tbno=RIGHT(@rightstr,@right-@rightlen)+Convert(nvarchar,@rightnum)
  
  end
 else
  begin
   Set @tbno=RIGHT(@rightstr,@right-@rightlenght)+Convert(nvarchar,@rightnum)
  end
 
 Set @return_no=@splitstr+ISNULL(@tbno,LEFT(@rightstr,@right-1)+'1')
 
 select @return_no AS Return_No

 
END

SET ANSI_NULLS OFF