Fix Error Establishing a Database Connection in WordPress (2025 Guide)

I have resolved hundreds of production outages caused by the WordPress error establishing a database connection while supporting Rocket.net, Hostinger, and NameSilo customers. This is the playbook I rely on to bring sites back online quickly and safely.

Overview and Quick Fix Summary

• In a rush? Make these checks before diving into deeper repairs.
• Confirm database credentials inside `wp-config.php`.
• Verify that MySQL is online and accepting connections.
• Repair or optimize tables that are marked as crashed.
• Temporarily disable plugins and themes introduced before the outage.
• Back up the database so you can roll back if needed.

Common Causes Explained

• The database error is a symptom. These are the triggers I encounter most often.
• **Incorrect credentials:** Mistyped database name, user, password, or host values.
• **Corrupted tables:** Power loss or a plugin conflict marks tables as crashed.
• **Server outages:** Saturated MySQL services or exhausted connections.
• **Plugin and theme conflicts:** Runaway queries or poor updates overwhelm the database.

Step 1 · Verify wp-config.php Credentials

WordPress needs the correct database name, username, password, and host. Even an extra space will trigger the connection error.

1. Log into your hosting file manager or connect via SFTP.
2. Open the `wp-config.php` file in the site root.
3. Confirm every credential matches what you see in the hosting control panel.

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

Providers often use custom database hosts such as internal IPs or socket paths. When in doubt, check documentation or open a ticket.

Step 2 · Confirm Hosting and MySQL Status

If credentials are correct, inspect the database server itself. Outages or throttled resources often trigger the error even when configuration files look fine.

• Review your host status page for downtime.
• Ask support if MySQL is under heavy load or restarting.
• Run a direct connection test with a lightweight PHP snippet.

<?php
$connection = mysqli_connect('DB_HOST', 'DB_USER', 'DB_PASSWORD');
if (!$connection) {
    die('Connection failed: ' . mysqli_connect_error());
}
echo 'Connected successfully';
?>

If the script fails, your configuration is solid. Escalate with logs because the issue lives inside the hosting environment.

Step 3 · Repair Corrupted Database Tables

Corruption happens. Use these repair options before restoring from a backup.

Repair via WordPress

Add the following constant temporarily, run the repair screen, then remove it.

define('WP_ALLOW_REPAIR', true);

Visit `/wp-admin/maint/repair.php` and choose **Repair and optimize database**.

Repair via phpMyAdmin

1. Select your database and check crashed tables.
2. Choose **Repair table** from the action dropdown.
3. Refresh the site to confirm the fix.

Always take a backup first. Hosting snapshots or plugins such as UpdraftPlus make rollback simple.

Step 4 · Troubleshoot Plugins and Themes

Intermittent errors often point to runaway queries triggered by recent updates. Deactivate plugins or switch themes to isolate the culprit.

• Rename `wp-content/plugins` to something like `plugins_disabled`. If the site loads, restore the folder name and reactivate plugins one at a time.
• Switch to a default theme such as Twenty Twenty-Four. If the site stabilizes, audit the custom theme for heavy queries.

Preventing Future Database Errors

• Stop the incident from repeating by following a preventative checklist.
• Enforce routine backups stored offsite.
• Monitor database slow query logs.
• Limit plugin installs and perform staged updates.
• Enable uptime monitoring so outages are caught instantly.

When to Call for Hosting Support

If you are still offline after completing these steps, escalate with a detailed ticket. Include timestamps, repair attempts, and the PHP connection test output. This speeds up triage with your host and keeps stakeholders informed.

Need someone to lead the recovery? Book a consultation and I will restore the site, harden the hosting, and document the incident for your team.