repair MDF file

How to Repair MDF File and Restore SQL Database Objects?

Although SQL Server is one of the most popular database programs, it has a major drawback. Just like any other computer file, an SQL database is also prone to corruption. So if you’re facing database corruption and looking for a way to fix it, you’ve come to the right place. In this article, I’ll share an easy manual solution to repair MDF file without using any 3rd party SQL Repair tool.

Microsoft SQL Server 

Today who doesn’t know about Microsoft SQL Server. According to a report, the popularity of SQL Server grew faster than any other database product during 2016.

Microsoft SQL Server is a popular Relational Database Management System (RDBMS) developed and provided by Microsoft Corporation. Being a database server, its primary function is to store and retrieve data as per the request by other software applications. Those applications may run either on the same computer or on another computer across a network (including the Internet). Microsoft SQL Server is available in multiple editions for different audiences and for different workloads. The workloads range from small single-machine applications to large Internet-facing applications with many concurrent users.

Microsoft SQL Server

SQL Server uses SQL aka structured query language to communicate with a database file for requesting information from it. ANSI (American National Standards Institute) says that it’s the standard language for any relational database management system. The main tasks of SQL statements are to update data in a database and retrieve data from it. Other relational database management systems which use SQL are Oracle, Sybase, Access, Ingres, etc.

File Types used in SQL Server

There are three file types used in Microsoft SQL Server: MDF, NDF, and LDF

  • MDF is a primary database file in SQL Server having .mdf extension. An MDF contains user data and objects, such as indices, columns, views, functions, values, tables, keys, stored procedures, triggers, default values, etc. Also, it can store the startup information for the database. Each database in the SQL Server has one primary MDF file. 
  • NDF is a secondary database file in SQL Server having .ndf extension. You can create as much NDF files as you want. Though the primary function of the NDF file is to spread data across multiple disks, it can also store user data. 
  • LDF is a LOG file in SQL Server having .ldf extension. It works as a backup file for the SQL Server database. The primary function of a LOG file is to restore SQL database at the time of accidental deletion and/or corruption. An LDF file contains log information, and every database has at least one log file.

SQL Database Corruption

I’ve seen a lot, especially database administrators, asking this question

How to prevent SQL Server database from going corrupt?

Since the MDF database is highly prone to corruption, you just can’t avoid it. Both SQL administrators and users often face database corruption. Since MDF file is the primary database, any sort of issue or error can corrupt the entire SQL database. Are you familiar with the most common reasons for SQL database corruption? If you ain’t, let me help you. Below are the most common reasons: 

  • Unexpected changes in SQL Server accounts
  • Accidental data deletion from the SQL database
  • Corruption in the header part of the database
  • Storage media corruption where SQL database file is stored
  • Network failure when a database is in working mode
  • Using compressed folders to store SQL database
  • Internal bugs in MS SQL Server program
  • Software malfunction or collision
  • Abruptly system shut down due to sudden power failure

How to Repair MDF File?

There are various reasons for database corruption in SQL Server. But there are only a few solutions which can help you fix it. If you have the backup of your SQL database, you can successfully restore the complete file from it. But if there’s no backup available, you have still a fair chance here. As I’ve already mentioned earlier that the LOG file (LDF) helps you restore SQL database at the time of accidental deletion and/or corruption, you should use it. 

Generally, a 3rd party SQL Repair tool is considered one of the best ways to repair MDF file. However, there’s an easy DIY trick you should use before purchasing any 3rd party tool. The manual trick I’m sharing here is easy and highly effective. Being an SQL Server user, you must be familiar with Microsoft SQL Server Management Studio. But do you know that you can repair MDF file by simply running a couple of database console commands?

Microsoft SQL Server Management Studio

Microsoft SQL Server Management Studio

SQL Server Management Studio is a software application primarily used to configure, manage, and organize all the components within the SQL Server. It was first launched with Microsoft SQL Server 2005. In Microsoft SQL Server Management Studio, you need to run these two database console commands (DBCC): DBCC CHECKDB and DBCC DBREPAIR

Step 1: First, open Microsoft SQL Server Management Studio on your system.

Step 2: On the toolbar, click the New Query button. This will take you to a new query page. Step 2: Now you need to write the SQL scripts on the page: 

EXEC sp_resetstatus [YourDatabase]; 

ALTER DATABASE [YourDatabase] SET EMERGENCY

DBCC checkdb ([YourDatabase])

ALTER DATABASE [YourDatabase] SET SINGLE_USER WITH ROLLBACK IMMEDIATE

DBCC DATABASE ([YourDatabase], REPAIR_ALLOW_DATA_LOSS)

ALTER DATABASE [YourDatabase] SET MULTI_USER 

Note: Replace the text YourDatabase with the original name of your database file. 

Step 3: Finally, click Execute to start the repairing process.

This will take a few seconds to repair MDF file. But remember, it may fail or not work in a case of severe corruption. In such a situation, you should consider using a professional SQL Repair tool. But when you search in the online marketplace, there are many options. And don’t forget, when there are too many choices, it’s always hard to choose the best one.

SysInfoTools SQL Repair Tool

When it comes to choosing the best solution to repair MDF file, the SQL Repair tool provided by SysInfoTools Software is a standout. Via this software, you can successfully restore SQL database objects like tables, views, stored procedures, programmability, triggers, default, and functions. During the recovery operation, it maintains the integrity of your data without causing any alteration. It can repair MDF file as well as NDF file, the secondary database. You just can’t detect the level of database corruption, i.e. how severe corruption is. But this software has two different recovery modes: Standard to handle minor corruption, and Advanced to handle severe corruption issues.

download now

SysInfoTools provides the free demo version of this SQL Repair tool. So before you can purchase the software, you must download its demo version for free evaluation. By using the demo version, you can scan the corrupt SQL database. Also, you can check the preview of your recoverable data prior to saving. And if you’re satisfied with the results, then only you should purchase the software.

Conclusion

In this article, we’ve discussed database corruption in Microsoft SQL Server. Also, we’ve gone the most common reasons for database corruption. Whenever corruption takes place in there SQL Server, we must repair MDF file. The article explained two different ways to repair MDF file, i.e. either you can use a manual solution or you can use a professional SQL Repair tool.

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