Are you worried about a corrupted or damaged SQL database? There are many reasons, like hardware crashes, power cuts, or buggy code that corrupts your SQL database and make them inaccessible for you. In such cases, it is important to restore the database with minimal possible downtime.
There are some simple methods that you can follow to fix your corrupted SQL database. You can also use professional and authentic third-party software to get your SQL database back. Here, we have mentioned few common reasons and methods that you can try to repair a corrupt MS SQL database.
What is MS SQL Server?
SQL is an acronym for Structured Query Language and is developed by Microsoft. SQL Server is a database management system that allows users to store and retrieve data from other applications. SQL Server uses three types of files to store and manage data; these are:
- Primary Files (MDF)
- Secondary Files (NDF)
- Log Files (LDF)
Primary SQL Server database files store user data and objects like Indexes, Columns, Views, Functions, Values, Tables, Keys, etc. These files are saved with .MDF extension and stores the startup information for the database.
Secondary files have .NDF as an extension and are optional files. You can create unlimited NDF files as per your need. These files spread data across multiple disks. You can use NDF files to store user data as well.
Log files that have extensions as .LDF is the backup files of SQL Server databases. You can use LDF files to restore the database in case of corruption as they store log information. Every database has a minimum of one log file.
What Causes MS SQL Database Corruption?
Before using any SQL database recovery tool or applying any method, one must check the exact cause of why the MS SQL database file is corrupted. There are several reasons that corrupt your SQL database files. Some common cause of the corruption are given below:
- Power Cut: Abrupt power cut or sudden shutdown of your device is the main reason for SQL corruption.
- Bugs: The bugs in your SQL files can damage your database and makes them unable to access properly.
- File Corruption: A virus or malware is also the main reason for corrupting any file stored within the SQL database.
- Hardware Problem: Instances may arise when the hardware that stores and runs the database can get damaged badly. In such cases, the page level corruption takes place and thus SQL database files are inaccessible.
Also check, some other factors that cause corruption in SQL databases are:
- Corrupted storage media where MDF files are stored
- Storing SQL database in compressed folders
- Modifications in SQL Server account
- Accidental data deletion or File header corruption
- Issues in disk drivers
- Network failure, etc.
How to Detect the Corruption in SQL Database?
Database Administrators are responsible to keep the database secure and available for use. But some corruption in database files makes the data remain unavailable. In such cases, it is important for the administrator to check the health of the database on regular basis. For this, you need to:
Run the database backup along with CHECKSUM
It is important for the administrator to include the CHECKSUM command with the backup command while running the database backup process. This command checks the database for any corruption and stops the backup process if any issue is found.
You can run the following command and see the result:
BACKUP DATABASE XYZ
TO DISK = ‘E:\Database Backup\XYZ.bak’
Run the DBDC CHECKDB command
DBCC CHECKDB command tells various information about the database, like the physical and logical integrity of its objects, index relationships, etc. If any of these checks fail, then it will report consistency errors in the database console command.
Basic Syntax of DBCC CHECKDB command is given below:
Before running this command, your system needs to fulfill the following prerequisites:
- Your device must have SQL Server Management Studio (SSMS).
- You need to have Administrator privileges to execute this command.
How do I Repair a Corrupt MS SQL Database File?
There are many tools available online that you can use for SQL database recovery. Here we are explaining Stellar Repair for MS SQL, which is a popular tool to repair corrupt SQL database (MDF and NDF) files. Microsoft MVPs and database administrators across the world recommend this software to restore MS SQL databases.
Stellar Repair for MS SQL uses a powerful algorithm and facilitates faster recovery of database objects. You can repair tables, triggers, indexes, stored procedures, etc., and that’s too with 100% integrity and precision.
How does Stellar Repair for MS SQL Works?
The tool that you select to repair your SQL database files is up to you. We are going with Stellar Repair for MS SQL as it is affordable and has a proven track record of repairing SQL server errors. The software supports SQL 2019, 2017, 2016, 2014, and other older versions.
Some salient features of Stellar Repair for MS SQL that makes it unique and perfect for SQL Database Recovery are given below:
- Faster Recovery with Parallel Processing
- Recovers Deleted Records from SQL Database
- Recovers All SQL Database Objects
- Recovers ROW and PAGE compressed Data
- Previews Recoverable Database Objects
- Automatically Saves Scan Results
- Works on both Windows and Linux Systems
Now, let’s discuss how exactly the software scans the corrupted SQL database files and repair them. Go through the detailed steps that are given below to know the working of Stellar Repair for MS SQL software:
Step 1: Firstly, download and install Stellar Repair for MS SQL software on your device.
Step 2: Launch the downloaded file and click the Browse or Find button to identify the corrupt SQL database MDF file.
Step 3: Once you get the SQL database MDF file that you have to recover, click Repair.
Step 4: Choose an appropriate scan mode among Advanced scan and Standard scan to repair the file. Click OK.
Step 5: After successful completion of the database file recovery process, click the OK button.
Step 6: Preview the recoverable database objects. Go to the File menu and tap the Save button.
Step 7: Enter all the asked details to connect to the SQL Server and click Next.
Step 8: Among fast saving and standard saving, choose the appropriate file saving mode and click Save.
Step 9: The status of the file saving process will appear on your device screen. It can be any of these: Completed, Processing, Pending, or Aborted.
Step 10: Once the saving process gets completed, a confirmation message with the same message will pop up on the screen.
Common Problems That Occur while Repairing a Corrupted SQL Database
There are some common issues that occur while repairing a corrupted SQL database. You must be familiar with these issues as these can make the recovery process even worse. Some of the things that you should avoid while recovering the corrupted database include:
- Rebooting the SQL server: Unfortunately, turning on the server after turning it off is not a good step. This may lead to the crash recovery of your database with no fixes.
- Clearing the procedure cache: If you clear the procedure cache and data, it will make the problem worse.
- Attaching/Detaching SQL Database: This purported repair can bother you while recovering the corrupted MS SQL database file. Attaching and detaching your SQL database can damage and worsen the recovery process.
In this article, we have discussed all SQL databases and their corruption. We have provided how an SQL database may become corrupt and effective methods, as well, that you can follow to get your files back. These steps will help you to fix SQL database corruption. We mentioned the best and the safest tool to deal with SQL database corruption. This tool is user-friendly and comes with several versions, depending on features. Hope this blog was helpful.