[Solved] Repairing a Microsoft SQL Server Database

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Microsoft SQL Server is one of the most popular databases, owing to its advanced internal architecture and high reliability. Consequently, most organizations use SQL Server databases to store all their critical business data. However, SQL Server is susceptible to various threats, such as database corruption and errors. Corruption in SQL Server database files renders database objects inaccessible. Several factors can contribute to the corruption of SQL Server database files. Here are some common causes of MDF file corruption:

• Errors in the SQL server itself
• Sudden system shutdown while the database was open
• Changes to the SQL account
• Virus infection
• Upgrading from an older version to a newer version of SQL Server can sometimes lead to database corruption.

Solution - DBCC CHECKDB

The DBCC CHECKDB command is used to check for inconsistencies in a database and perform repairs. If your database is corrupted, using this command to repair the database might be a good option. You can use this command to repair specific objects or components rather than the entire database.

To run this command, follow these steps:

DBCC CHECKDB (database_name)

This command checks tables, storage, and quality and consistency metrics, and displays the results in a list. If your database is large, repairs can take a long time.

Solution - MS SQL Recovery Tool

However, if the MDF file is severely damaged, the DBCC CHECKDB command can easily fail, and manual solutions require a high level of technical expertise. Hence, it is recommended to use some reliable third-party software to repair corrupt SQL databases.

The MS SQL Recovery tool is a highly professional and reliable SQL repair utility. It recovers database components like tables, triggers, indexes, keys, rules, and stored procedures from SQL databases, along with deleted records. It supports MS SQL Server 2016, 2014, 2012, 2008, and earlier versions.

Here are the steps to perform Microsoft SQL database repair: 1. **备份 Database**: 在开始任何修复操作之前，确保先备份你的数据库。这可以防止在修复过程中可能出现的任何意外数据丢失。 2. **启动 SQL Server Management Studio (SSMS)**: 打开安装在你计算机上的SQL Server Management Studio。 3. **连接到 Server**: 在对象资源管理器中，点击 "Connect" > "Database Engine"，然后输入服务器名称和凭据以连接到SQL Server。 4. **选择需要修复的 Database**: 在已连接的服务器下面，展开 "Databases" 文件夹，找到并右键点击你需要修复的数据库。 5. ** Detach the Database**: 选择 "Tasks" > "Detach..."，这将断开数据库与SQL Server的连接。 6. **Check the Database Files**: 检查数据库的.MDF（主数据文件）和.LDF（日志文件）是否完整无损。如果文件损坏，可能需要从备份恢复或使用第三方工具进行修复。 7. **Use DBCC CHECKDB Command**: 如果数据库文件看起来是完好的，可以在命令行或通过SQL查询窗口运行 `DBCC CHECKDB` 命令来检查数据库的完整性。例如: ``` DBCC CHECKDB ('YourDatabaseName') ``` 如果该命令发现错误，它会尝试自动修复。 8. **Attach the Database**: 如果 `DBCC CHECKDB` 成功修复了问题，你可以重新附加数据库。回到SSMS，右键点击 "Databases"，选择 "Attach..."，然后添加并确定.MDF和.LDF文件的位置。 9. **Monitor and Test**: 重新附加数据库后，监控其性能并运行一些查询以确保一切正常。如果还有问题，可能需要更高级的修复方法或专业帮助。 请注意，这些步骤只适用于常规修复情况。复杂或严重的问题可能需要更专业的解决方案，如使用SQL Server的还原功能，或者联系Microsoft支持。

Before you proceed with the repair, back up your MS SQL database by simply copying it or using backup software.

Step 1: Select the corrupted database to be recovered

< li > Launch the MS SQL Recovery tool. < li > Select the corrupt database file by clicking on 'Browse' (two dots) or 'Search'. < li > After selecting the file, click on 'Repair' to initiate the analysis process.

Caution: You must stop the SQL Server service before you use this utility.

Step 2: Repair the corrupted database

The software displays all the recoverable items in a tree view. These items are listed in the left pane. Select the component that you want to restore. In the window, click the Export button.

Step 3: Export to a Database or Script

• Choose to export database objects to a database, or choose to export the project as a script. • If you chose to Export to Database, provide the required information and select the target database.

A window will appear asking for the credentials to connect to the server and the location to save the recovery project. Click OK to start the repair process.

Note: You will need to restart the SQL Server service before clicking OK.

Prevention

It's always wise to prevent problems rather than solve them after the fact. Here are some ways to keep your SQL Server databases from becoming corrupt.

• Regularly back up the database.
• Conduct routine checks on memory, network monitoring, and hardware error inspections to prevent failures and hardware issues.
• Create scripts to monitor and identify slow queries in the database.
• Use antivirus software to protect your computer from malware.

Conclusions

Corruption is best prevented through a thorough backup regimen, regular tests of file-recovery procedures, and checks for integrity.