How to Repair SQL Database- A Detailed Guide
MS SQL Server is widely used as one of the relational databases containing a sophisticated internal structure and is highly reliable. To save the essential data, most of the organizations use the SQL database. But sometimes SQL database resulting in database corruption in SQL server due to virus infections, malfunctioning of the operating system, corrupted file system, etc. This is because the MDF file gets corrupted and there is a need to repair MDF files. Therefore this blog focuses on ‘how to repair SQL Database’ by explaining various methods. Reasons for Database Corruption in SQL Server- In a SQL Server server, there may be various possible explanations for corruption. As everyone knows, the main server files are the MDF files of SQL database. They store all user data but corruption in MDF files can corrupt the entire database. Therefore, we will discuss all the possible reasons for corruption in MDF files 1. If a client has stored the SQL database in a compressed folder it is likely to overwrite the MDF file. 2. Any data may have been accidentally deleted by a user. 3. Corruption of all MDF files in storage media. 4. Any modifications or improvements will be made to a SQL Server account. If the SQL database is in use and there is a network error between them, this leads to MDF file corruption. 5. Virus attacks, hard disk failure, irregular machine shutdown, and sudden power failure are other possible reasons that cause MDF file corruption. 6. If the header of the file is corrupted, it will result in MDF file corruption. 7. Disc drivers defected. These are the reasons for creating MDF file corruption. Now, let's move ahead to know manual techniques. How to recover data from corrupted SQL Server Database via Manual Techniques? There are usually two cases where you can use this approach to fix the master database file of SQL Server. Let's continue! Method 1: Solve SQL Server Database in Recovery Pending Mode The server undergoes the condition of Recovery Pending when a resource-related issue occurs during recovery. In this case, there is no fraud or harm to the SQL Server database. Nonetheless, it is unavailable due to some folder or machine resources failure. You need to detach the existing database and reattach it using T-SQL query to fix Recovery Pending status in SQL Server. Go through this article once to get this process in depth. Method 2: Repair SQL Database Marked as Suspect or Corrupted The suspect mode can cause damage or corruption to the primary filegroup. That is why the SQL database is not usable. You need to use the DBCC Check command to restore Suspect database. Here we have defined a general procedure that works successfully to repair SQL Server Suspect Mode Error server. This process is divided into several steps. So, let's continue!! Phase 1: Enable SUSPECT Database to Emergency Mode This mode allows only read-only access of the system administrator to the database In fact, only members of the sysadmin will set the EMERGENCY State. Run the following query on the panel to make the database in EMERGENCY mode: ALTER DATABASE DATABASE_NAME SET EMERGENCY Phase 2: Verify Damage Level DBCC CHECKDB (DB Name) request need be run and the errors should be analyzed as: DBCC CHECKDB (Database_Name) Phase 3: Repair Command Execution There are three repair modes available with DBCC CHECKDB that can be used to restore the database from EMERGENCY mode to functional mode: REPAIR FAST:- The syntax of backward compatibility can be retained. This means that in SQL Server 2008, you can run the SQL Server 2005 database folder. There are no strong maintenance acts. If you want to solve the problem of backward compatibility, make sure that the server is in SINGLE USER mode rather than EMERGENCY status. Use the following methods to make the database in SINGLE USER MODE: Method 1: By GUI Approach 1. Choose the database and make a right-click on it. 2. Go and hit on Options. 3. Visit the Restrict Access option and go to the drop-down button. Then, choose the SINGLE_USER option >> OK button. Method 2: By T-SQL Query You can also use T-SQL to switch the mode of the database to SINGLE USER. To do this, execute the SSMS query below. ALTER DATABASE DATABASE_NAME SET SINGLE_USER\ REPAIR_FAST Command After setting up the Single USER Mode database, execute the query below to repair the SQL Server database. DBCC CHECKDB (N ‘Database_Name’, REPAIR_FAST) WITH ALL_ERRORMSGS, NO_INFOMSGS; GO REPAIR_REBUILD:- This repair command is preferred for the SQL database because the risk of data loss is much lower. Ideally, REPAIR FAST performs all the repair procedures. It also performs some time-consuming repairs, including the reconstruction of indexes. To use this, execute the query below. Notice: Database in SINGLE_USER Mode. DBCC CHECKDB (N ‘database name’, REPAIR_REBUILD) WITH ALL_ERRORMSGS, NO_INFOMSGS; Read Also- How to Recover Corrupted MySQL Database? Method 3: Setting Database to MULTI_USER Mode Use the following query and change the database mode into multi-user mode once the database is repaired successfully: ALTER DATABASE DATABASE_NAME SET MULTI_USER All these are the manual approaches to repair SQL database. But there may be some chance to data loss and other data may be corrupted. So, it is better to use a third-party utility to directly repair MDF files. Use SQL Database Recovery software to perform MDF recovery that can result in repairing SQL Database. Final Verdict This blog explained various manual methods repair SQL database that can resolve database corruption in the SQL server. But there are many drawbacks with manual ways so to handle this an expert solution has been provided.