Using php script to connect to database

I was using the following script to connect to the database:

<?php // Define database connection constants define('DB_HOST', ''); define('DB_USER', 'verdant'); define('DB_PASSWORD', ); define('DB_NAME', 'ourverdantgarden_nativeplants'); define('DB_PORT', '3306'); ?>

but it’s not working anymore. I don’t know if the port number has changed. I have checked the password and user.

Any thoughts?