SQL restores data before modification, how SQL restores data How SQL restores data

First, if it is an oracle database and it has just been deleted, you can execute the following statement:

insert

into the table name.

select

from. asof

timestamp

to_timestamp('2007-07-2310:20:00',yyyy-mm-dd

hh24:mi:ss');

Change the date and time in the statement to the most recent time before you misoperated.

Two, if it's a sqlserver database, then.

1. First of all, make a log backup of the database after mistakenly deleted;

backup

log database name.

todisk='The path and the name of the log backup file'

2. Restore the database to the date of the last full database backup;

restore

database

The name of the database. from

disk='The path and the name of the database backup file'

withreplace,norecovery3、Use the log backup in step 1 to restore the database to the moment you deleted it by mistake;

restore

log database name.

fromdisk='The path and the name of the log backup file'

withrecovery,stopat='The date and time in the 2009-4-24 statement are changed to the most recent time before you misoperated.

Third, if you have done a database backup before the modification, you can create a new library, restore the backup, export the table data, and then import it into the current database

Backing up a database to another disk in real time, there are several different ways to do this, such as:

1. If there are two servers, you can do dual-machine hot standby.

2. Only one server can be used as disk mirroring.

3. You can also use special database backup software.

A full backup of the recovery database and preparation for log recovery.

restore

database

pubsfrom

diskn'c:\backups\'

withnorecovery

Now you can roll the logs forward to the right point in time and make the database available for use. Note that stopat is prohibited while the database is executing bulk logs.

restore

logpubs

fromdisk=n'c:\backups\'

withrecovery,stopat='02/11/2002

Example 2: A statement that uses database tags to restore logs to a predefined point in time.

Place a tag in the transaction log. Note that the flagged transaction must commit at least one update to mark the log.

begintran

mymark

withmark

update

setmarktime

getdate()

commit

tranmymark

Back up the transaction log as you normally would.

backup

logpubs

todisk='c:\backups\'

withinit

You can now restore the database to a log marker. Start by recovering the database and making it ready for log recovery.

restore

database

pubsfrom

disk=n'c:\backups\'

withnorecovery

Now restore the log to the point in time that contains the marker and make it ready for use. Note that stopat is prohibited while the database is executing bulk logs.

restore

logpubs

fromdisk=n'c:\backups\'

withrecovery,stopat='02/11/2002

microsoft

sqlserver

Development team.

Try it, I use it in Oracle.

create

tabletablename_bak

asselect

fromtablenameasof

timestamp

to_timestamp('20081126103435','yyyymmdd

hh24miss');

tablename is the table you want to restore, tablename bak is the backup table of tablename, and the data of tablename bak is restored to tablename.

103435'Change it according to your own situation, change it to the time before you delete the data, but this method can only find out about 2 days of data, and it is estimated that it will not work after a long time.

Method: Step 1: Select the database to be restored, right-click, and select Restore under the task.

Step 2: Select "Source Device" and click on the file behind it to select "....

Step 3: Add the database that needs to be restored, and the restored database file is suffixed with the backup file (bak);

Step 4: Select the added restore noisy file, find the "Option" on the upper left corner, check the first item (overwrite the existing database), and click OK.

Precautions. 1. Be sure to remember to overwrite the existing database;

2. When performing database operations, please disconnect any use of the current database (e.g., query, database connection use).

1. Run Recovery for SQL Server first.

2. Click: Next > Next--" to enter the Recovery Configuration interface.

3. Then check Search for Deleted Records, and select the log file path of the database you want to recover.

4. Click next-》to start the recovery.

5. Click Next, and select the target database where the recovered data is stored.

6. Finally, click Finish, and then complete the data recovery.

Suggestion: Develop a good habit of backing up the data in the table before updating the data, and then delete it after confirming that there is no problem after the update.

In addition, when updating, use the process to judge, check the data after the update, and commit if it meets the requirements, otherwise rollback.

The SQL 2000 error cannot be restored unless a backup is available before the modification. The problem of backing up a database to another disk in real time is more complex, and SQL 2000 itself has a scheduled task to back up data to any accessible disk location at a certain time, such as 12 p.m. every day. If you must require a real-time backup, consider purchasing professional data backup software, or a real-time backup software that you can search for and share online.

Try it, I use it in Oracle.

create table tablename_bakas select * from tablename as of timestamp to_timestamp('20081126 103435','yyyymmdd hh24miss');

tablename is the table you want to restore, tablename bak is the backup table of tablename, and the data of tablename bak is restored to tablename.

20081126 103435'Change it according to your own situation, change it to the time before you delete the data, but this method can only find out about 2 days of data, and it is estimated that it will not work after a long time.

1. Run Recovery for SQL Server first.

2. Click: Next > Next--" to enter the Recovery Configuration interface.

3. Then check Search for Deleted Records, and select the log file path of the database you want to recover.

4. Click next-》to start the recovery.

5. Click Next, and select the target database where the recovered data is stored.

6. Finally, click Finish, and then complete the data recovery.

You can't do it in this situation, my cousin has used Haiyu safe before You can try it.