How to Repair Corrupt MDF File in SQL - Easy Tricks

SQL is a conventional programming language designed to manipulate relational databases. An MDF (Master Data file) file holds the essential components of the database. Whenever we create a new database in SQL Server, it stores the data in an MDF file. Imagine, you are working in an SQL Server and there’s a power cut that leads to improper shutdown. Consequently, the file might get corrupted. In that case, you have manual methods to repair corrupt MDF file in SQL. However, they may incur data loss. The SQL Recovery Tool will be the better alternative to help you solve the problem.

What Are the Reasons Behind SQL Server MDF File Corruption?

Listed below are the main reasons that could result in the corruption of SQL database MDF Files. Understand these potential causes to ensure the smooth functioning of the SQL Server Database.

• Hardware Failure issues like power failures, hard drive crashes, disk errors, etc.
• Sudden shutdowns do not provide enough time for the MDF File to complete necessary transactions leading to corruption.
• Unsuccessful or partial restoration of backup files due to database mismanagement can corrupt the MDF file.
• Corruption may arise due to bugs in SQL Server or the Operating System.
• Malicious software or third-party applications can also corrupt MDF files.

How To Repair Corrupt MDF File in SQL?

There are in total three ways. Out of which, two of them require a bit of technical understanding. On the other hand, SQL MDF Recovery Tool does it automatically. These are some recommended methods to repair damaged SQL MDF file and recover the data.

Method 1: Using the DBCC CHECKDB Command

In some cases, where a recent valid backup is unavailable or outdated, one can use this method. However, it may not be able to fully restore all database components. Users have to be familiar with SQL Server commands, only then they can run these commands.

1.     First, execute the following command: 

ALTER DATABASE YourDatabaseName SET SINGLE_USER WITH ROLLBACK IMMEDIATE;

     2.     Now, check if there is a corrupted database  

DBCC CHECKDB ('YourDatabaseName');

    3.     There are a few repair options that you can choose from:

DBCC CHECKDB ('YourDatabaseName', REPAIR_ALLOW_DATA_LOSS);

 

This option is a high-risk option. It does repair the corrupted files at the cost of potential data loss

 

DBCC CHECKDB ('YourDatabaseName', REPAIR_FAST);

 

This one is suitable for fixing small corruption issues. It does not    

repair, rather than rebuild the MDF file quickly. 

a. Execute the following command:

 

DBCC CHECKDB ('YourDatabaseName', REPAIR_REBUILD);

 

It does not work for FILESTREAM data. It is effective for rebuilding corrupted pages and recovering missing rows in non-clustered indexes.

Method 2: Using Restoring From Backup

This is the most reliable and safest method to repair corrupt MDF File in SQL, especially if you have a valid backup.

1.     First, check if you have a valid backup of the database or not.

Run the SQL Command: 

RESTORE VERIFYONLY FROM DISK ='C:\Backup\YourDatabaseBackup.bak';

      2.    Now, to restore the backup to a new database, execute the command: 

RESTORE DATABASE NewDatabaseName FROM DISK = 'C:\Backup\YourDatabaseBackup.bak' WITH MOVE 'YourDatabaseName_data' TO 'C:\SQLData\NewDatabaseName.mdf',

Limitations: Any post-backup data modifications will not be recovered. 

Method 3: Using an Automated SQL MDF Recovery Tool

SQL MDF File Recovery Tool is a robust and safe tool for repairing SQL Server MDF files without losing any data. It lets users browse MDF files and successfully retrieves Functions, Indexes, Triggers, Views, Rules, Tables, and Stored procedures. In addition to this, it offers Standard and Advanced recovery modes for repairing severe corruptions and restoring SQL Server Database with accuracy. The software is easy to handle and is compatible with all Windows OS. 

 

Here are the step-by-step instructions to initiate the process to repair damaged SQL MDF File :

1.     Download and Launch the software on your PC. 

2.     Click on Open and select the MDF File Path.

3.     Now, choose the corrupt MDF File from the list and then click Open.

4.  Browse through Select Recovery Mode. Choose as per the severity of file corruption 

5.     Then, click Open to start the process. The MDF File opens up.

6.     After that, click on Save SQL Data. 

7.     Lastly, Click OK to save the data.

 

Conclusion:

When an MDF file becomes corrupted, backups are the most reliable way to restore the data. However, if a backup is not available, you can try repairing the MDF file using the DBCC CHECKDB command in SQL Server. If the command doesn’t work as expected, the automated tool provides an advanced solution that can repair corrupt MDF file in SQL without data loss.

Frequently Asked Questions

Q. What causes MDF file corruption?

Ans- There can be several reasons that might corrupt your MDF file. A sudden power shutdown, any malicious software containing a virus, full disk storage issues, or an instant SQL Server crash can corrupt your MDF file.

 

Q. Is it possible to recover deleted records from an MDF file?

Ans- Yes, one can definitely recover deleted data from an MDF file. This can be done either using SQL Server Transaction Logs or a professional MDF Recovery Tool. Provided that your deleted folder is still intact after scanning through the software.