WordPress: Error Establishing a Database Connection

What this error means & how to recognize it

• The site displays only “Error establishing a database connection,” often on every front-end page.
• /wp-admin/ is also unavailable because it uses the same database connection.
• The error may begin after a migration, hosting change, database restore, manual wp-config.php edit, password reset, or database-server restart.
• If only selected pages fail while other database-backed pages work, the issue may be page-, plugin-, theme-, or query-specific rather than a complete database connection failure.

Root causes, ordered by likelihood

1. Incorrect credentials in wp-config.php — DB_NAME, DB_USER, DB_PASSWORD, or DB_HOST no longer matches the current database configuration. This is especially common after a migration, restore, password change, or manual edit.
2. An unavailable MySQL or MariaDB server — the service may have stopped, crashed, or become unavailable because of a hosting resource problem.
3. The wrong database host — localhost may be incorrect when the database runs on another server or container, while a remote host value may no longer match the current environment.
4. Missing database-user privileges — the user may exist but not be assigned to the WordPress database or may lack the privileges needed to use it.
5. Corrupted database tables — an interrupted write, unclean shutdown, or disk problem can damage tables, but this is generally less likely than a configuration or availability problem.

How to fix it

1. Confirm the scope of the failure

Open the public site and /wp-admin/. If both show the connection error, continue with the database checks below. If only one page or function fails, inspect the specific plugin, theme, query, or application error instead of assuming the entire database connection is unavailable.

2. Check whether MySQL or MariaDB is running

On a VPS or dedicated server where you are responsible for service management, check the relevant service status. These commands are read-only and require shell access:

systemctl status mysql

If the server uses MariaDB, check:

systemctl status mariadb

On shared or managed hosting, use the hosting panel’s database status information or ask the provider to check the service and resource limits. Restart a database service only when you administer that server, have appropriate authorization, and have confirmed that the operational impact is acceptable; a restart can interrupt active database connections.

3. Verify the four database settings in wp-config.php

Use SFTP or the hosting file manager to open wp-config.php. Compare these values with the current database details in the hosting panel or migration records:

• DB_NAME — the database WordPress should use
• DB_USER — the database username
• DB_PASSWORD — the current password for that user
• DB_HOST — the database server address or host setting

Check for a stale database name, an outdated password, an incorrect host, or accidental whitespace and quoting changes. Do not assume the previous values remain valid after a migration, hosting move, database restore, or password reset.

4. Test the same connection outside WordPress

Use phpMyAdmin or the MySQL command line with the exact database name, username, password, and host from wp-config.php. This test should use the same environment and credentials that WordPress uses.

• If the direct connection fails, investigate the credentials, database host, server availability, or network access before changing WordPress files.
• If the direct connection succeeds, the basic server and credential path works; continue by checking database-user assignment, privileges, and table health.

Never post the password or the complete wp-config.php file when requesting assistance.

5. Confirm database-user access and privileges

In the hosting panel’s database-user section, verify that the user from wp-config.php is assigned to the correct WordPress database and has permission to read and modify its tables. This check is particularly important after restoring a database under a new account or creating a replacement user.

If you administer MySQL directly, an authorized administrator can inspect the account’s grants with SHOW GRANTS. Correct the user-to-database assignment or privileges only after confirming the intended database and account. Then repeat the direct connection test and reload the site.

6. Check for table problems only after the connection works

If the database server is available, the exact credentials work in a direct test, and the user has access, inspect the WordPress tables in phpMyAdmin or through an authorized database tool. CHECK TABLE can report table problems.

Create or verify a current database backup before attempting any repair. REPAIR TABLE is mainly relevant to supported MyISAM tables and is not a universal repair method. Do not run repair commands repeatedly when checks report no corruption; return to the host, configuration, privileges, and server logs for further diagnosis.

7. Verify the complete site after the fix

Load several public pages and /wp-admin/. If both work, clear only relevant caching layers if stale output remains. If either area still fails, capture the exact current message and review the server or hosting logs rather than assuming the original connection problem is unchanged.

Prevention & how to verify the fix

• Store current database name, user, host, and password details in a protected password manager or equivalent secure record.
• After every migration or hosting change, test both the public site and /wp-admin/ before completing the move.
• Maintain regular database backups and periodically confirm that a restore is possible.
• Record which database user is assigned to each WordPress database so a restore or user replacement does not silently remove access.
• Review hosting resource alerts and database-service events when available, particularly after unexpected restarts or recurring connection failures.
• Limit access to wp-config.php and avoid sharing its contents or credentials in support requests.

Frequently asked questions