Repair WordPress database settings in wp-config.php

When to use this guide

Use this guide when WordPress shows Error Establishing a Database Connection, especially after a migration, password rotation, host move, database rename, or restore from backup.

Before you start

• Back up wp-config.php before editing.
• Open the real WordPress root, not wp-config-sample.php.
• Do not paste database passwords, salts, or keys into public tickets or screenshots.
• Use the hosting panel or secret manager as the source of truth for credentials.

Step 1: Locate the database constants

define('DB_NAME', 'database_name_here');
define('DB_USER', 'username_here');
define('DB_PASSWORD', 'password_here');
define('DB_HOST', 'localhost');

Expected output is one active set of constants. If a managed host uses environment variables or an included config file, follow that pattern rather than adding conflicting constants.

Step 2: Compare each value

Step 3: Test the database login safely

mysql -h DB_HOST -u DB_USER -p DB_NAME

Expected output is a successful MySQL/MariaDB prompt. If login fails, the credentials or privileges are wrong. If login works but WordPress fails, check host-specific socket/port syntax, table prefix, PHP database extensions, or whether WordPress is reading a different config file.

Step 4: Check charset and collate without guessing

Most sites should keep their existing DB_CHARSET and DB_COLLATE. Do not change charset during an outage unless a migration guide or host support confirms it. Incorrect charset changes can make recovery harder.

Managed hosting notes

Some providers store database credentials outside editable files or regenerate wp-config.php. In those environments, compare panel values, database user permissions, and selected PHP app root before editing manually.

Expected outputs

After a correct credential repair, direct database login succeeds, WordPress stops showing the database connection message, and the access log changes from a database failure response to a normal page load or a different actionable error. If direct login fails with Access denied, fix user/password/privileges. If it fails with Unknown database, fix the database name or restore/import the missing database. If it fails with connection timeout, check DB_HOST, firewall, socket, port, and database service health.

If it still fails

Confirm that the WordPress files you edited are the files served by the domain. Multi-site, staging-to-production copies, symlinks, and container mounts often leave an old wp-config.php active in a different path. Also confirm that the table prefix matches the imported tables; a valid login with a wrong prefix can lead to a different WordPress error after the database connection is restored.

Verify

Reload the site and wp-admin once. Confirm the database connection error disappears, then check the HTTP status and WordPress debug log. If the site changes to a 500, switch to WordPress 500 troubleshooting.

Rollback or escalate

If the edit fails, restore the backup of wp-config.php. Escalate with the redacted database constants, database host, database name, table prefix, migration date, and whether direct database login works. Never send the real DB_PASSWORD or salts in plain text.