Great Thanks in Advance!

I am the regular reader of ur site.where i have some doubt and confusion regarding the rollback for delete after commiting it.

Can u please explain with an example,so that it could be useful for many folks like me.

I am using Sql Server 2008
accedently data delete from table but I have no Transactional Backup and my database in full recovery .
I have Full Backup of last 1 Month .so plz suggest me how to recover data from table …plz it is very urgent ….

in name column,i’l have raj,ravi,ashok,poonam,pooja,etc and i want to add ‘s with every name. So,what can i do.

This SYSDATETIME() is not get a proper value and sql server 2005 show error message.

I have one table (Example – table name)

In that table two fileds is there 1) slno – int, 2)name – varchar(50)

I entered the records

slno Name

1 a
2 b
3 c

First I Delete one record using Delete Command

delete from example where slno =’1′

after that

truncate the table using truncate command

truncate table example

Now

I roll back record of 1

how can i?

i try this but i can’t? Please help me

I have tested the pinal dave post.. Truncate can be rollback whether the database is Full recovery model or simple recovery model…

Still am not clear please explain me. I am using SQL SERVER 2008

thanks
Raj…..-)

The TRUNCATE command Drop The Table and And Recreate it.

–STEP 1. Creating DB
SET NOCOUNT ON
CREATE DATABASE TEST
GO
ALTER DATABASE TEST SET RECOVERY FULL
USE TEST
GO

–STEP 2. Creating table with some data (100 rows)
CREATE TABLE data (f1 INT IDENTITY)
GO

INSERT data DEFAULT VALUES
GO 100
select COUNT(*) AS CNT,’1st 100′ AS Remark FROM data
–STEP 3. Performing full backup
BACKUP DATABASE TEST TO DISK=’D:\test_full.bak’ WITH INIT
GO

–The above full backup will guarantee the first hundred recovery.

–===================
INSERT data DEFAULT VALUES
GO 100
select COUNT(*)AS CNT,’2nd 100 AFTER full backup’ AS Remark FROM data
–====================
–STEP 4. Performing log backup
DECLARE @date DATETIME

–variant1: Date mark just before truncation
SET @date = DATEADD(s, 0, GETDATE())
select @date as TimeOfRB

–variant2: Date mark after truncation
–SET @date = DATEADD(s, 1, GETDATE())

TRUNCATE TABLE data
WAITFOR DELAY ’00:00:10′
select COUNT(*) AS CNT,’trun’ AS Remark FROM data
–This log backup now has all the 100 records inserted after full backup
–making total count to 200 records in the table
BACKUP LOG TEST TO DISK=’D:\test_log.bak’ WITH INIT

–STEP 5. Restoring Test DB.
USE MASTER
RESTORE DATABASE TEST FROM DISK=’D:\test_full.bak’ WITH NORECOVERY, REPLACE
RESTORE LOG TEST FROM DISK=’D:\test_log.bak’ WITH RECOVERY, STOPAT=@date
GO
USE TEST
GO
–This will return count less than 200
select COUNT(*)AS CNT ,’last’ AS Remark FROM data
go
USE MASTER
DROP DATABASE TEST

–select * from emp

begin transaction

truncate table emp

–rollback transaction

above is the code snap short please try and let me know.

I have a different observation on this rolling back / recovering the data lost by truncate. The example provided by Alexander is perfect. But here the data truncated is not exactly recovered by restoring the log file to a point before truncate. We are taking a full backup after inserting 100 records, and then truncating the table. So restoring the full backup took care of retrieving all records not the transaction log.

I have a different case to prove that the data lost due to a TRUNCATE can be recovered, but not 100%. As storage engine only records the deallocation of pages in log, and releases the pages and its corresponding extent for allocation there is definite possibility for data loss. The percentage of data loss depends on how soon we take a log backup and the new requests for page allocation. My simple guess is the transaction log backup we are taking itself can grab those deallocated pages of TRUNCATE and cause data loss. To prove this I have made little changes to Alexander’s code as below. I have added a INSERT statement (highlighted in ‘==’) after taking full backup. These inserts are logged in only transaction log, not backedup during full backup.

– STEP 1. Creating DB
SET NOCOUNT ON
CREATE DATABASE TEST
GO
ALTER DATABASE TEST SET RECOVERY FULL
USE TEST
GO

– STEP 2. Creating table with some data (100 rows)
CREATE TABLE data (f1 INT IDENTITY)
GO

INSERT data DEFAULT VALUES
GO 100

– STEP 3. Performing full backup
BACKUP DATABASE TEST TO DISK=’c:\test_full.bak’ WITH INIT
GO

–The above full backup will guarantee the first hundred recovery.

–===================
INSERT data DEFAULT VALUES
GO 100
–====================
– STEP 4. Performing log backup
DECLARE @date DATETIME

– variant1: Date mark just before truncation
SET @date = DATEADD(s, 0, GETDATE())

– variant2: Date mark after truncation
–SET @date = DATEADD(s, 1, GETDATE())

TRUNCATE TABLE data
WAITFOR DELAY ’00:00:03′
–This log backup now has all the 100 records inserted after full backup
–making total count to 200 records in the table
BACKUP LOG TEST TO DISK=’c:\test_log.bak’ WITH INIT

– STEP 5. Restoring Test DB.
USE MASTER
RESTORE DATABASE TEST FROM DISK=’c:\test_full.bak’ WITH NORECOVERY, REPLACE
RESTORE LOG TEST FROM DISK=’c:\test_log.bak’ WITH RECOVERY, STOPAT=@date
GO
USE TEST
GO
–This will return count less than 200
select COUNT(*) AS CNT FROM data
go
USE MASTER
DROP DATABASE TEST

This test gives us a different count every time which confirms a data loss. I am glad to see this forum and will appreciate your feed back.

Take transactional backup, Then try to restore database using Stop at function, give the time when you think the deleted record was available, and database will be restored till that time, and the record will be available. This process will create a new database. Be careful dont over write the old database.

Hope this helps,
Imran.

I’m understanding now. So, To make a rollback over an alter data. I need to restore the last full backup and next the differential and log backup before to make the change?

I have any other way to rollback the sentence update?

Thank you for posting clarification and as well we are in agreement. I respect your additional research as well writing about this on your blog http://www.siusic.com/wphchen/recover-data-using-transaction-log-144.html

You are always welcome to comment and participate here to help community.

Kind Regards,
Pinal Dave ( http://www.SQLAuthority.com )