一个恢复数据库的问题如何解决？

/*--恢复数据库

--邹建 2003.10--*/

/*--调用示例
--完整恢复数据库
exec p_RestoreDb @bkfile='c:db_20031015_db.bak',@dbname='db'

--差异备份恢复
exec p_RestoreDb @bkfile='c:db_20031015_db.bak',@dbname='db',@retype='DBNOR'
exec p_backupdb @bkfile='c:db_20031015_df.bak',@dbname='db',@retype='DF'

--日志备份恢复
exec p_RestoreDb @bkfile='c:db_20031015_db.bak',@dbname='db',@retype='DBNOR'
exec p_backupdb @bkfile='c:db_20031015_log.bak',@dbname='db',@retype='LOG'

--*/

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[p_RestoreDb]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop procedure [dbo].[p_RestoreDb]
GO

create proc p_RestoreDb
@bkfile nvarchar(1000), --定义要恢复的备份文件名
@dbname sysname='',     --定义恢复后的数据库名,默认为备份的文件名
@dbpath nvarchar(260)='', --恢复后的数据库存放目录,不指定则为SQL的默认数据目录
@retype nvarchar(10)='DB', --恢复类型:'DB'完事恢复数据库,'DBNOR' 为差异恢复,日志恢复进行完整恢复,'DF' 差异备份的恢复,'LOG' 日志恢复
@filenumber int=1, --恢复的文件号
@overexist bit=1,        --是否覆盖已经存在的数据库,仅@retype为'DB'/'DBNOR'是有效
@killuser bit=1     --是否关闭用户使用进程,仅@overexist=1时有效
as
declare @sql varchar(8000)

--得到恢复后的数据库名
if isnull(@dbname,'')=''
select @sql=reverse(@bkfile)
,@sql=case when charindex('.',@sql)=0 then @sql
else substring(@sql,charindex('.',@sql)+1,1000) end
,@sql=case when charindex('',@sql)=0 then @sql
else left(@sql,charindex('',@sql)-1) end
,@dbname=reverse(@sql)

--得到恢复后的数据库存放目录
if isnull(@dbpath,'')=''
begin
select @dbpath=rtrim(reverse(filename)) from master..sysfiles where name='master'
select @dbpath=reverse(substring(@dbpath,charindex('',@dbpath),4000))
end

--生成数据库恢复语句
set @sql='restore '+case @retype when 'LOG' then 'log ' else 'database ' end+@dbname
+' from disk='''+@bkfile+''''
+' with file='+cast(@filenumber as varchar)
+case when @overexist=1 and @retype in('DB','DBNOR') then ',replace' else '' end
+case @retype when 'DBNOR' then ',NORECOVERY' else ',RECOVERY' end

--添加移动逻辑文件的处理
if @retype='DB' or @retype='DBNOR'
begin
--从备份文件中获取逻辑文件名
declare @lfn nvarchar(128),@tp char(1),@i int

--创建临时表,保存获取的信息
create table #tb(ln nvarchar(128),pn nvarchar(260),tp char(1),fgn nvarchar(128),sz numeric(20,0),Msz numeric(20,0))
--从备份文件中获取信息
insert into #tb exec('restore filelistonly from disk='''+@bkfile+'''')
declare #f cursor for select ln,tp from #tb
open #f
fetch next from #f into @lfn,@tp
set @i=0
while @@fetch_status=0
begin
select @sql=@sql+',move '''+@lfn+''' to '''+@dbpath+@dbname+cast(@i as varchar)
+case @tp when 'D' then '.mdf''' else '.ldf''' end
,@i=@i+1
fetch next from #f into @lfn,@tp
end
close #f
deallocate #f
end

--关闭用户进程处理
if @overexist=1 and @killuser=1
begin
declare @spid varchar(20)
declare #spid cursor for
select spid=cast(spid as varchar(20)) from master..sysprocesses where dbid=db_id(@dbname)
open #spid
fetch next from #spid into @spid
while @@fetch_status=0
begin 
exec('kill '+@spid)
fetch next from #spid into @spid
end 
close #spid
deallocate #spid
end

--恢复数据库
exec(@sql)

--查询分析器中执行,看执行结果是什么:
RESTORE headeronly from disk='d:a.bak'

RESTORE filelistonly from disk='d:a.bak'

RESTORE LABELONLY from disk='d:a.bak'

结果
RESTORE headeronly from disk='d:a.bak'

yjs_data 备份 NULL 4 NULL 0 1 2 sa SERVER yjs_data 539 2003-09-13 23:26:47.000 1580544 12000000005900001 12000000006300001 12000000005900003 0 2003-12-09 13:11:56.000 2003-12-09 13:11:56.000 0 168 2052 196609 80 4608 8 0 760 SERVER 0 {22166F91-A1B8-43B9-9BF9-72795331E45E} {22166F91-A1B8-43B9-9BF9-72795331E45E} Chinese_PRC_CI_AS

RESTORE filelistonly from disk='d:a.bak'

yjs_data_Data C:Program FilesMicrosoft SQL ServerMSSQLdatayjs_data_Data.MDF D PRIMARY 1638400 35184372080640

RESTORE LABELONLY from disk='d:a.bak'

NULL NULL 1 1 {7635169B-0000-0000-0000-000000000000} 1 0 NULL Microsoft SQL Server 4608 2003-12-09 13:11:56.000

--1.要将.mdf文件恢复出来,yjs_data是数据文件名,如果出错,改用:yjs_data_data
restore  DATABASE [yjs_data] FILE = N'yjs_data'
from  DISK = N'd:a.bak'

USE MASTER
GO

SP_CONFIGURE 'ALLOW UPDATES',1 RECONFIGURE WITH OVERRIDE
GO

UPDATE SYSDATABASES SET STATUS =32768 WHERE NAME='yjs_data'
Go

sp_dboption 'yjs_data', 'single user', 'true'
Go

DBCC CHECKDB('yjs_data')
Go

update sysdatabases set status =28 where name='yjs_data'
Go

sp_configure 'allow updates', 0 reconfigure with override
Go

sp_dboption 'yjs_data', 'single user', 'false'
Go