Database connection error

WordPress keeps your pages, orders and settings in a database. "Error establishing a database connection" means it can't reach that database, so it can't build any page. Your content is usually still there.

How to fix it

Work from the top, because the first causes are the most common. WP Moo sees the site again on its next check.

The database server is down or overloaded

Ask your host whether the database server is running. Does the error come and go? Then the server is probably overloaded, often by too many visitors or bots at once, or the hosting account hit its limit on database connections.

The password or database name changed

This usually happens after a move or after someone changed the database password in the hosting panel.

Open wp-config.php in your hosting panel's file manager.
Compare DB_NAME, DB_USER, DB_PASSWORD and DB_HOST with the database details in your hosting panel.
Correct what's different and save the file.

The database is damaged

Does /wp-admin say "One or more database tables are unavailable"? Ask your host to repair the database, or to restore it from a backup. Don't restore a backup of a shop without checking first: you lose the orders placed since that backup.

For your developer

Test the login from the server, with the values from wp-config.php:

mysql -h DB_HOST -u DB_USER -p DB_NAME -e 'select 1'

To repair tables from WordPress, add define('WP_ALLOW_REPAIR', true); to wp-config.php and open /wp-admin/maint/repair.php. Anyone can open that page while the line is there, so remove it straight after. With WP-CLI, wp db check and wp db repair do the same.

We match the error on the markup of WordPress's own database error page, see WordPress failure signatures.

Something unclear on this page? Email [email protected]