How to read or modify the mdf/log file

See this post when we visit webpage yesterday

Among them
SQL Server 2005 – When Checksum fails when the data recovery possible
You can see, he passed 16 hexadecimal compiler, the simulation of a destructive test
"By 16 hex editor to introduce checksum failed"
I took this him not to go, this step is not to play.,
First he that modify the screenshot, exactly is to modify the MDF or log file.?
It can be seen clearly by 16 hexadecimal compiler?
Or is this the Microsoft internal black technology can modify the see?
Ask questions
If you really can clearly read, it is much more convenient, such as access to log in the deleted record what

Started by Winnie at February 01, 2016 - 10:05 PM

The premise is not encrypted database, data file (.Mdf) can use Visual Studio to sixteen hexadecimal format to open and edit.
See the table data in the database.

Posted by Douglas at February 13, 2016 - 10:27 PM

On the restoration of deleted records, should be directly from the log file recovery did not.
But MSSQL has provided some methods can realize the handy recovery,
If a database snapshot, a point in time restore the database, LZ can understand.

Or find the nearest database backup and restore for other name database, and then to extract deleted records.

Posted by Douglas at February 22, 2016 - 11:09 PM

You want to modify the mdf/log content directly, it can be black Microsoft database.

Gets the log record, there are special logexplorer read.

Posted by Rory at March 09, 2016 - 11:20 PM

Logexplorer is not 2008 cannot be used., , ,
As for the reduction of what,,, the file is too big, too slow, and non full mode is not available

The premise without database encryption? Refers to what? I was in accordance with the test cases that webpage steps to create, but opened the 16 hex file, unable to find the corresponding word.
Or that his test case is 2005 to 2008R2,, I can't play this?

Posted by Winnie at March 11, 2016 - 11:36 PM

The DBCC page also can view the data, and a command, -- the direct write data page
DBCC writepage (database ID, fileid, ID, offset, the number of bytes,0x6161616161)

Can directly modify the data in the MDF, these studies are unlikely to directly read, log and file data

Posted by Toby at March 15, 2016 - 12:22 AM

The default database is not encrypted.:
1 discharged from the database.
2 to find the corresponding data file (.Mdf) -> -> right; property -> -> add everyone full control permissions.
3 right -> open -> select Visual Studio open.

Posted by Douglas at November 24, 2016 - 5:29 PM

Of course is to modify the MDF or NDF file. CHECKSUM applies only to the data file. LDF is not CHECKSUM.
If encryption is not enabled, the MDF and NDF files can be read, can be directly used DBCC to read a data page.

Posted by Enoch at December 09, 2016 - 5:56 PM

Study on the calculation of offset, really painful, although successfully changed, can directly modify the page, but there is a problem
The goods cannot reflect the destructive tests I want to do ah

Posted by Winnie at December 20, 2016 - 6:16 PM

The following test,
use DBAP2

create table csdn
(username char(20))

insert into csdn(username)
 select 'starseeker7'

select username from csdn


(1 row(s) affected)

1 discharged from the database.
2 to find the corresponding data file (.Mdf) -> -> right; property -> -> add everyone full control permissions.
3 right -> open -> select Visual Studio open.
To open the Find dialog according to [Ctrl]+[F] Visual Studio, input the search content"starseeker7",
Can be positioned to Oh.
Find results,

Posted by Douglas at December 28, 2016 - 7:07 PM

Can reflect the destructive tests you want, such as the DBCC writepage if the number of bytes you write is 10, is 10 bytes written on the back,
But the field type you are 6, then it will play a destructive, causing the surface damage, I do a test

Posted by Toby at January 01, 2017 - 7:41 PM

Well, still no results, test, ,
I'll study, most of which, what mistakes

Posted by Winnie at January 05, 2017 - 9:52 PM

Although you can change, but you can also attach? Or restore to normal, be able to read it?
I also tried, the database to read.

Posted by Rory at January 06, 2017 - 9:02 PM

The LZ reference card
Should be want to simulate the storage medium damage, I test only provide the 'failure' method, laughed.
As for how to restore, should look at the LZ reference card, I haven't scan.

Posted by Douglas at January 07, 2017 - 9:46 PM

If you want to change, please make a backup, because the data modification is a log record, when the data is illegally modified, possible error data inconsistency, so that you can not do anything, be careful Oh.

Posted by Rory at January 09, 2017 - 8:19 PM