If you see "Error establishing a database connection" on WordPress, try these steps: 1. Check database credentials in wp-config.php. 2. Ensure the database server is running. 3. Repair the database using WordPress repair mode. 4. Increase PHP memory limit. 5. Test connection with a standalone script. 6. Restart web and database services.

If you are seeing the "Error establishing a database connection" message on your WordPress site, it means WordPress cannot communicate with the database. Here are several methods to resolve this issue:

The operating environment of this tutorial: Dell XPS 13, Windows 11

1. Verify Database Credentials in wp-config.php

This step ensures that WordPress is using the correct database name, username, password, and host. A typo or incorrect detail here will prevent connection.

• Access your website files via FTP or your hosting file manager.
• Locate the wp-config.php file in the root directory.
• Open the file and check the following lines:

  define('DB_NAME', 'your_database_name');
  define('DB_USER', 'your_username');
  define('DB_PASSWORD', 'your_password');
  define('DB_HOST', 'localhost');
  

• Confirm these values match your actual database credentials from your hosting panel.
• Save changes and reload your site.

2. Check if the Database Server is Running

The MySQL or MariaDB service might be stopped due to server issues or crashes. Restarting the service can restore connectivity.

• Log in to your hosting control panel (e.g., cPanel, Plesk).
• Navigate to the MySQL Databases section.
• Verify that the database status is active. If not, look for an option to restart the database server.
• If using a VPS or dedicated server, use SSH to run:

  sudo systemctl status mysql

  or

  sudo systemctl status mariadb

• If inactive, start it with:

  sudo systemctl start mysql

3. Repair Corrupted WordPress Database

Database corruption can cause connection failures. WordPress has a built-in repair mode to fix common issues.

• Edit the wp-config.php file again.
• Add this line above the "That's all, stop editing!" comment:

  define('WP_ALLOW_REPAIR', true);

• Visit https://yoursite.com/wp-admin/maint/repair.php in your browser.
• Click “Repair Database” or “Repair and Optimize Database.”
• After completion, remove or comment out the added line for security.

4. Increase PHP Memory Limit

Insufficient memory can interrupt database processes. Increasing the limit may resolve unexpected disconnections.

• Edit the wp-config.php file.
• Add this line:

  define('WP_MEMORY_LIMIT', '256M');

• Alternatively, edit the php.ini file on your server and set:

  memory_limit = 256M

• Save the file and restart your web server if necessary.

5. Test Database Connection with a Standalone Script

Use a simple PHP script to isolate whether the issue is specific to WordPress or a broader server configuration problem.

• Create a file named test-db.php in your site’s root folder.
• Add the following code, replacing placeholders with your database details:

  <?php $connection = mysqli_connect('localhost', 'your_username', 'your_password', 'your_database');
  if (!$connection) {
      die('Connection failed: ' . mysqli_connect_error());
  }
  echo 'Connected successfully';
  ?>
  

• Access the file via browser: https://yoursite.com/test-db.php.
• If it fails, the issue is server-side. If it succeeds, the problem lies within WordPress files or configuration.

6. Restart Web and Database Services

Temporary glitches in services can break connections. Restarting them often restores normal operation.

• If you have server access via SSH, run:

  sudo systemctl restart apache2

  or

  sudo systemctl restart nginx

• Then restart the database:

  sudo systemctl restart mysql

• Wait a few moments and reload your WordPress site.

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