In enterprise-level applications, Microsoft SQL Server plays a central role in data storage and management. However, like all complex systems, SQL Server can encounter a variety of errors and problems that can affect the normal operation of your business.
The purpose of this article is to provide a practical guide for database administrators and technicians to help identify common types of SQL Server errors, understand the causes of errors, and master methods of how to repair SQL Server to ensure the stability and efficiency of data services.
Common Errors and Quick to Repair SQL Server
1. Error 18456: Login Failed
This is one of the most common errors, which usually indicates an attempt to access SQL Server with invalid credentials.
Quick Solution: Check whether the login credentials are correct, including user name and password; confirm the authentication mode of SQL Server (Windows authentication or mixed mode) and adjust it accordingly; if necessary, reset the SA password or create a new login account.
Command: No specific command, solve the problem by interface operation.
2. Error 9002: Transaction log for database is full
This error occurs when the transaction log file reaches its maximum size or the disk space is insufficient.
Quick Solution: Expand the size of the transaction log file. You can do it through SQL Server Management Studio (SSMS), right-click on the database -> Properties -> File Groups -> Select Log Files -> Modify the “Auto-growth” setting or directly increase the initial size.
Command: ALTER DATABASE [DatabaseName] MODIFY FILE (NAME = N’LogFileName’, SIZE = XX MB)
3. Error 40613: The connection is broken and recovery is not possible
The database is in recovery state, probably because of an abnormal shutdown or the recovery process has not completed.
Quick Solution: Wait for the database to finish recovery automatically. If it does not finish for a long time, you can try to recover it manually by using the “Recover Database…” option in SSMS, or check the SQL Server error logs for more specific error messages.
Command: No specific command is required, operate through SSMS or wait for automatic recovery.
4. Error 823: I/O Error
This indicates that SQL Server encounters hardware problems when reading or writing data files.
Quick Solution: First, check the hardware (hard disk, RAID controller, etc.) to make sure there is no physical damage. Then, run DBCC CHECKDB to check database consistency. If necessary, consider restoring the data from a backup.
Command: DBCC CHECKDB (‘DatabaseName’) WITH ALL_ERRORMSGS, NO_INFOMSGS
How to Repair SQL Server without SQL Program
MTM Database Recovery for SQL is a data recovery tool designed for Microsoft SQL Server that recovers damaged or inaccessible SQL databases and supports reading and repairing .MDF and .NDF files. This software is especially suitable for those who are experiencing database corruption issues where standard repair methods do not work.
The steps to repair SQL Server using MTM Database Recovery for SQL are as follows:
Step 1: Download and install MTM Database Recovery for SQL software. After the installation is complete, start the MTM Database Recovery for SQL program.
Step 2: In the software interface, click “Recovery” option, browse and select the SQL database file (such as .MDF or .NDF) you need to repair.
Step 3: Check “Recover deleted data” and click “Recover” button, the software will start scanning the selected database files to detect recoverable data and structures.
Step 4: After the scanning is completed, the software will display a list of recoverable database objects, including tables, views, stored procedures, etc. You can preview some of the data. You can preview some of them to confirm the recoverability and integrity of the data.
Step 5: Finally, select the database objects you want to recover or recover all of them, either export to database or choose to export as a CSV file.
Other Commands: SQL Server Repair Database
- Repair Database Consistency Problems: DBCC CHECKDB (‘DatabaseName’) WITH REPAIR_ALLOW_DATA_LOSS (Note: This command may cause data loss, please use with caution)
- Restore Database: RESTORE DATABASE [DatabaseName] FROM DISK = ‘BackupFilePath’ WITH REPLACE
Conclusion
Here is the troubleshooting guide on how to repair SQL Server mentioned above. Maintaining the stable operation of SQL Server and resolving all types of errors in a timely and effective manner is crucial. By understanding the common types of errors and their solutions, database administrators can locate the problem faster and take action to minimize the impact on the business.
Remember that, regular backups, monitoring the status of your SQL Server, and performing timely maintenance are best practices for preventing and minimizing the occurrence of failures. We hope that this article will be a great help to you when maintaining your SQL Server.