存储过程与事务实现转账

USE [master]
GO
/****** Object:  Database [BankSystem]    Script Date: 11/20/2013 16:12:45 ******/
CREATE DATABASE [BankSystem] ON  PRIMARY 
( NAME = N'BankSystem', FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\DATA\BankSystem.mdf' 

, SIZE = 2304KB , MAXSIZE = UNLIMITED, FILEGROWTH = 1024KB )
 LOG ON 
( NAME = N'BankSystem_log', FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\DATA

\BankSystem_log.LDF' , SIZE = 576KB , MAXSIZE = 2048GB , FILEGROWTH = 10%)
GO
ALTER DATABASE [BankSystem] SET COMPATIBILITY_LEVEL = 100
GO
IF (1 = FULLTEXTSERVICEPROPERTY('IsFullTextInstalled'))
begin
EXEC [BankSystem].[dbo].[sp_fulltext_database] @action = 'enable'
end
GO
EXEC sys.sp_db_vardecimal_storage_format N'BankSystem', N'ON'
GO
USE [BankSystem]
GO
/****** Object:  Table [dbo].[CardInfo]    Script Date: 11/20/2013 16:12:45 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[CardInfo](
	[PKID] [int] IDENTITY(1,1) NOT NULL,
	[CardNum] [nvarchar](19) NOT NULL,
	[Balance] [money] NULL,
PRIMARY KEY CLUSTERED 
(
	[PKID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) 

ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[Transfer_Event]    Script Date: 11/20/2013 16:12:45 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Transfer_Event](
	[PKID] [int] IDENTITY(1,1) NOT NULL,
	[FromCardID] [nvarchar](19) NOT NULL,
	[ToCardID] [nvarchar](19) NOT NULL,
	[TransMoney] [money] NULL,
	[OccurTime] [datetime] NULL,
PRIMARY KEY CLUSTERED 
(
	[PKID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) 

ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  StoredProcedure [dbo].[TranserMoney]    Script Date: 11/20/2013 16:12:46 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
--实现转账过程的存储过程实现如下（0代表成功，1代表转账源账户不存在，2代表转账目标账户不存在，3代表金额不足,4代表失败）
CREATE procedure [dbo].[TranserMoney]
(
@fromCardNum varchar(19),        --转账源卡号
@toCardNum  varchar(19),         --转账目标卡号 
@tansMoney Money,                --转账金额
@statue int  output              --0代表成功，1代表转账源账户不存在，2代表转账目标账户不存在，3代表金额不足,4代表失败
)
as
     declare @cardNum varchar(19)
     declare @balance Money=(select balance from CardInfo where  CardNum=@fromCardNum)
      --开始事务 
      if @balance is not null
      begin
       declare @exist int=(select COUNT(*) from CardInfo where  CardNum=@toCardNum)
       if @exist !=0
      begin
          if @balance>=@tansMoney
          begin
          
          begin transaction 
          declare @level int=0
            update CardInfo set Balance=Balance-@tansMoney where CardNum=@fromCardNum
            set @level=@level+@@ERROR
            update CardInfo set Balance=Balance+@tansMoney where CardNum=@toCardNum
            set @level=@level+@@ERROR
             insert into Transfer_Event(FromCardID,ToCardID,TransMoney,OccurTime)values

(@fromCardNum,@toCardNum,@tansMoney,GETDATE())
            set @level=@level+@@ERROR
            if @level=0
            begin
               set @statue=0
                  commit transaction   --提交事务   
            end
            else
            begin
            set @statue=4
              rollback transaction   --回滚事务          
            end
          
          end 
          else
          begin
          set @statue=3
          end
      end
       else
      begin
      set @statue=2
      end
      end
      else
      begin
      set @statue=1
      end
GO
/****** Object:  Default [DF__CardInfo__Balanc__014935CB]    Script Date: 11/20/2013 16:12:45 ******/
ALTER TABLE [dbo].[CardInfo] ADD  DEFAULT ((0)) FOR [Balance]
GO

　下面的测试代码

 --0代表成功，1代表转账源账户不存在，2代表转账目标账户不存在，3代表金额不足,4代表失败

declare @statue int
 exec TranserMoney '101','103',100,@statue output
 select @statue
 
 select * from cardinfo
select * from Transfer_Event