SQL备份数据库

USE [master]
GO
/****** 对象:  StoredProcedure [dbo].[DataBaseRestore]    脚本日期: 12/18/2015 14:17:11 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO



ALTER PROCEDURE [dbo].[DataBaseRestore] 
AS

declare @device varchar(255)
declare @path varchar(255)
declare @dbname varchar(255)
declare @filename varchar(255)
declare @cmd varchar(255)

set @dbname = 'SmartPas'
set @path = 'D:\database\' --备份文件存储位置
set @filename = @dbname+'_Ts_'+ convert(char(8),getdate(),112)+substring(replace(convert(char(9),getdate(),114),':',''),0,3)+'.bak' 
set @device=@path + @filename 
declare @sql nvarchar(4000),@par nvarchar(1000)
if not exists( 
 select * from master..sysdatabases 
  where name=@dbname
  )
 begin
 --select @flag='db not exist'  /*数据库不存在*/
    return 2
 end
else
 begin
 --存在数据库就判断文件是否存在
   declare @num int --申明一个接受返回值的变量
   EXEC xp_fileexist @device ,@num output -- 执行文件存在否的验证 存在返回1 不存在返回0
   if(@num = 1) --如果存在就执行还原
   begin
      --begin tran tDeal
      --begin try

           exec ('alter database '+@dbname+' set offline WITH ROLLBACK IMMEDIATE;')

           select @sql='RESTORE DATABASE @db_name FROM DISK=@filename with '
           select @sql=@sql +' replace'
           select @par='@db_name nvarchar(128),@filename nvarchar(260)'
           execute sp_executesql @sql,@par,@db_name=@dbname,@filename=@device 

           exec ('alter database '+@dbname+' set online with rollback IMMEDIATE;')
          --删除备份文件（这句可以去掉） 
          --set @cmd = 'del ' +  @device 
          --exec master..xp_cmdshell @cmd 
      --end try
      --begin catch    
          --rollback tran tDeal
          --return 0
      --end catch
   end
 end