MSSqlServer 通过sql语句 还原数据库（已有备份文件）

declare  @dbname varchar(20)   --数据库名称
declare  @filename varchar(200)  --数据库备份文件 路径

set @dbname='MyTest'
set @filename='D:MyTest.bak'

--关闭现有数据库连接
declare @i int 

declare cur cursor for 
select spid from sysprocesses where db_name(dbid)= @dbname 
 open cur fetch next from cur into @i while @@fetch_status=0 
 begin
   exec('kill '+@i) fetch next from cur into @i 
 end
 close cur 
 deallocate cur
--已关闭数据库连接

--还原数据库
RESTORE DATABASE @dbname FROM DISK=@filename WITH replace
--还原数据库完毕