差异备份的恢复问题
A :情况是这样的 create database test create table t(a int) insert into test..t select 1 然后进行一次完整备份 backup database test to disk='c:\test.bak' insert into test..t select 2 再进行一次完整备份 backup database test to disk='c:\test.b
A : 情况是这样的
create database test
create table t(a int)
insert into test..t select 1
然后进行一次完整备份
backup database test to disk='c:\test.bak'
insert into test..t select 2
再进行一次完整备份
backup database test to disk='c:\test.bak'
insert into test..t select 3
此时用 restore database test from disk='c:\test.bak' with file=1
结果为 1, 此为正确
用 restore database test from disk='c:\test.bak' with file=2
结果为 1,
2 此也为正确
当表t中为1,2,3的时候,在插入一条纪录结果为1,2,3,4然后进行一次差异备份
backup database test to disk='c:\test.bak' with differential
然后往执行delete from t 删除所有纪录
我现在想恢复最后的那次差异备份(结果为1,2,3,4),用语句改如何实现呢?
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下面的是详细的过程,在我的电脑上测试成功:
--清除环境,防止现有的数据影响测试结果
exec master..xp_cmdshell 'del c:\text.bak'
if exists(select * from master..sysdatabases where name='test')
drop database test
go
--创建数据库
create database test
go
--打开创建的数据
use test
go
--创建测试表
create table t(a int)
--切换回master数据库
use master
go
--插入数据1
insert into test..t select 1
go
--然后进行一次完整备份
backup database test to disk='c:\test.bak'
go
--插入数据2
insert into test..t select 2
go
--再进行一次完整备份
backup database test to disk='c:\test.bak'
go
--插入3,4
insert into test..t select 3
insert into test..t select 4
go
--差异备份:
backup database test to disk='c:\test.bak' with differential
--删除数据库
drop database test
--还原数据库和差异数据库备份
--还原完整备份
restore database test from disk='c:\test.bak' with file=2,norecovery
--还原差异备份的内容
restore database test from disk='c:\test.bak' with file=3,recovery
--显示恢复后的数据
select * from test..t
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都已经说的好明白了,怎么可能会不行呢?
前段时间我就做过类似程序的!
必须说明的是:在恢复差异备份时,必须恢复最后一次的完整备份!!(切记)
而且下面的两个语句必须同时执行,即放在一个事务中。
restore database test from disk='c:\test.bak' with file=离你要恢复的差异备份最近一次的完整备份号,norecovery
restore database test from disk='c:\test.bak' with file=你要还原的差异备份号,recovery
具体的备份号可以从下面得到:(你可以认真研究一下backupfile,backupset,backmediaset,backupmediafamily几个表,可以发现规律)
select backup_start_date as 备份时间,position as 备份号,
case type when 'D' then '完整备份' when 'I' then '差异备份' end as 备份类型
from msdb..backupset where database_name='test'
and media_set_id in
(select distinct media_set_id from msdb..backupmediafamily where physical_device_name='c:\test.bak')
order by position
如果还不行的话,可以给我留言~
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---执行下面的序列:
create database test
go
use test
go
create table test..t(a int)
insert test..t select 1
backup database test to disk='c:\test.bak'
insert test..t select 2
backup database test to disk='c:\test.bak'
insert test..t select 3
insert test..t select 4
backup database test to disk='c:\test.bak' with differential
delete test..t
go
--下面开始恢复:
restore database test from disk='c:\test.bak' with file=2,norecovery --对应你最后一次的完整备份
restore database test from disk='c:\test.bak' with file=3 --对应你要还原的差异备份
go
select * from test