Repair MySQL Database – Error Establishing a Database Connection

Database corruption is one of the most problematic situations for a DBA to ever come across. If you find that your shiny MySQL database is no longer running or you receive an error establishing a database connection, it’s probably the corruption. Whenever a MySQL database gets corrupt, there’s no way to open it until you repair it. In this article, we’ll learn how to repair MySQL database manually. And if the manual tricks fail to repair the database, you should use a professional MySQL Recovery tool to recover MySQL database.

What is MySQL Database?

A database is basically a collection of structured data. In a database, the elements are made addressable for more efficient processing and analysis. It may be anything, from a simple shopping list to a picture gallery or a large amount of information on a corporate network. It needs a database management system to add, access, and process the data stored in the database. Computers can handle a large amount of data and information with ease. And a database management system like MySQL Server plays an important in computing, as a stand-alone application or as a part of other programs.

MySQL databaseMySQL is a relational database management system based on the structured query language (SQL). It was first released in January 1998. And now it has become the most popular open-source database in the world due to its excellent performance, ease of use, high reliability, and cost-saving features. It’s commonly used in a wide range of applications which include e-commerce, web databases, data warehouses, logging, and distributed applications. Like any other database management system, MySQL also creates a database file to store the data and information. Generally, MySQL database files are saved with FRM, MYD, and MYI extensions.

  • The FRM file contains the table definitions
  • The MYI file is MyISAM index file
  • And, the MYD file contains the table data

Database Corruption in MySQL

Database corruption is one of the worst nightmares in the life of a database administrator. We store precious data in a database, and each day the dataset grows bigger and bigger. A database file is highly prone to corruption due to its large size and complex file structure. Any sort of issue or error may put the database at high risk of corruption. And whenever corruption takes place in the database files, it may result in a data loss situation. Throughout my IT professional career, I’ve seen many corruption issues.

recover MySQL database

A MySQL database ain’t immune to corruption. It may get corrupt at any time due to various reasons even if you’re seriously taking almost every precaution to prevent database corruption. Below are the most common reasons for database corruption in MySQL Server:

  • Virus Infection
  • Improper Shutdown
  • Hardware Failure
  • Software Malfunction
  • Storage Media Crash

So whenever you face database corruption due to any reason, the MySQL database becomes inaccessible. Even sometimes you may encounter error messages. One such common error message is, “error establishing a database connection”.

error establishing a database connection

In such a crucial time, a valid backup file can be a lifesaver. If you have a backup, you can restore the MySQL database from it. But if there’s no backup available, you must repair MySQL database file.

Users might also be interested in Repair MDF File via Microsoft SQL Server Management Studio

How to Repair MySQL Database?

Generally, data recovery experts recommend a professional MySQL Recovery tool whenever corruption takes place in the MySQL database. It can successfully recover MySQL database which is corrupted due to any reason. However, you should try to repair MySQL database by using a couple of easy DIY tricks. If the MySQL table is corrupted, you can try to repair it with phpMyAdmin.

If you’re encountering MySQL time-out errors or any unexpected behavior, maybe one or more MySQL tables are corrupted. You should try to repair MySQL table in order to fix the issue.

How to Repair MySQL Table?

You can use phpMyAdmin to repair MySQL table. You can access phpMyAdmin from Siteworx account. Follow these simple steps:

  • First, log in to your SiteWorx account.
  • On the left-hand side panel, select Hosting Features > MySQL > PhpMyAdmin.
  • Now select the corrupt MySQL database. Then select the check box corresponding to the corrupted table.
  • Now click Repair table from the “With selected list.

There’s one more way to repair MySQL table. This time you need to use the MySQL CLI (command-line interface). Follow these simple steps:

  • First, log in to the MySQL Server by using SSH (Secure Shell).
  • Now on the command-line interface, enter this command
    mysql -u (username) -p
    Note: Replace the “username” text with your correct username. Also, remove the brackets.
  • Enter your password.
  • Now enter this command
    use (databasename);
    Note: Replace the “databasename” with your actual database name, and remove the brackets.
  • Enter the command
    show tables;

Keep in mind that there’s no way to repair multiple tables with a single command, unlike phpMyAdmin. Make sure you enter one command per table.

  • In order to check a table for errors, enter this command check
    table (yourtablename);
    Note: Replace the “yourtablename” with the actual table name, and remove the brackets.
  • In order to repair a table, enter this command
    repair table (yourtablename)
    Note: Replace the “yourtablename” with the actual table name, and remove the brackets.
  • Now type quit to return to the command prompt.

If these DIY tricks don’t work for you, maybe this time you should use a professional MySQL Recovery tool. There are many vendors in the online marketplace to choose from. But it’s always difficult to choose the best MySQL Recovery tool.

MySQL Recovery Software

Over the past few years, SysInfoTools Software has become a popular brand name in the field of data recovery. The MySQL Recovery tool provided by SysInfoTools can repair MySQL database and recover data from both InnoDB and MyISAM storage engines used in MySQL. It can successfully fix all the corruption errors including “error establishing a database connection”. Via this software, you can restore database objects like tables, keys, table properties, data types, views, triggers, etc. You can save all the recovered data into a new MySQL database or in the form of SQL compatible scripts at any location.

Before purchasing this MySQL Recovery tool, you should download its demo version for free evaluation. By using the demo version, you can scan and repair MySQL database file. Also, you can check the preview of the database file prior to saving. The saving feature is disabled in the demo version. To save the recovered data, you must purchase the licensed version.

Conclusion

Just like any other database, MySQL database is also prone to corruption. In this article, we’ve learned about database corruption in MySQL Server and it’s common reasons. Also, we’ve learned how to repair MySQL database with a couple of easy manual tricks. But when the manual tricks fail or don’t work, it’s always better to switch to a professional solution like MySQL Recovery tool.

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