How to Repair MDF Files - A Complete Solution

Summary: In this blog, we discuss why MDF files get corrupted and how you can fix them easily. If you're struggling with a damaged MDF file and need a solution, this guide will help. Here, we get to know about different manual methods to repair MDF Files. After that, we discuss how to recover MDF files quickly and effectively with the professional method SysInfo MS SQL Database Recovery.

Reasons to Repair Corrupt MDF File

1. If important SQL database files or data are affected, repairing them can help restore or recover the database.
2. Needed when data is lost due to upgrades, migrations, or unexpected system crashes.
3. During database maintenance like shrinking or moving files, data may get corrupted or lost.
4. If the file system is damaged, MDF files may get corrupted and chances of data loss.

Methods to Repair Corrupt MDF File

Here, we study manual and professional methods to recover MDF files.

Method 1: How to Repair MDF File Using DBCC CHECKDB Command

1. First, run DBCC CHECKDB to detect integrity issues and corruption in the MDF file as given below:

 DBCC CHECKDB Test1

2. Then, if you face any error in accessing the file, change the database status to Emergency mode to provide read-only access to the administrator. Set the database to EMERGENCY mode with this command:

ALTER DATABASE Test2 SET EMERGENCY

3. Now, run DBCC CHECKDB again to check for corruption. If found, it suggests a repair option. Before repairing, set the database to single-user mode using the command below.

Command = ALTER DATABASE Test 2 SET SINGLE_USER

4. After this, you can repair the database by using the following options:

REPAIR_FAST

REPAIR_REBUILD

REPAIR_ALLOW_DATA_LOSS

5. Use REPAIR_FAST to quickly check logical consistency. It doesn’t repair but maintains compatibility.

Command = DBCC CHECKDB (‘DB Name’, REPAIR_FAST)

6. Now, use REPAIR_REBUILD to fix corrupt pages or missing rows in non-clustered indexes. It doesn’t repair databases with FILESTREAM data. Use this command.

Command = DBCC CHECKDB (‘DB Name’, REPAIR_REBUILD)

7. Finally, if other options fail, use REPAIR_ALLOW_DATA_LOSS as a last resort. It may cause data loss. Use the below command.

Command = DBCC CHECKDB (‘DB Name’, REPAIR_ALLOW_DATA_LOSS)

Method 2: Repair MDF File Using Recent Database Backup

1. If your MDF file is corrupted, first try restoring it from a backup. Check its integrity with RESTORE VERIFYONLY before restoring. Use this command.

Command = RESTORE VERIFYONLY FROM DISK = 'backup_with_checksum.bak’

2. Now, this command helps you verify if the backup file is readable, its format is valid, the backup set is complete, and CHECKSUM is present in it.

When verification is complete, run the below command.

Command = RESTORE DATABASE OfficeWorks2025

                     FROM DISK = 'Z:\SQLServerDataBackups\OfficeWorks2025.bak' ;

                     RESTORE DATABASE sysinfodb

Method 3: Professional Method to Repair Damaged MDF File

Sysinfo MDF Recovery Pro is a reliable tool that recovers crucial data from corrupted MS SQL database files. It repairs corrupt/inaccessible/damaged database files from any SQL server version. This tool quickly repairs and recovers corrupt MDF and NDF file extensions without harming the original data. Similarly, it allows users to repair MDF file recovery with two Recovery Modes- Standard and Advanced Mode. Moreover, it comprises different features like preserving original data structure, a preview option, and efficiently recovering deleted records from corrupt MySQL databases. It supports all the versions of Windows OS.

Steps to Restore MDF File SQL Server

1. Run the SysInfo SQL Database Recovery Tool.
2. Now, search the SQL Database files(.mdf) from your PC
3. Then, select the recovery mode as per the level of corruption.
4. After that, the scanning process gets started to recover corrupt data.
5. Choose the folders you want to restore and click Save SQL data.
6. Then, a wizard pops up on your screen: Select SQL server database or SQL script to download data.
7. Once you perform the selection, Tap OK to start the restoring process.
8. Finally, you will find a pop-up showing the process completed and your MDF File Corrupted issue resolved.

Conclusion

In this blog, we have seen if your MDF file is corrupted, you can restore it from a backup. If no backup is available, use DBCC CHECKDB to repair it. If that doesn’t work, try the professional tool to repair MDF file. It offers several features to repair corrupt and damaged files without harming the original data.