Empty means as "no records" or "blank page"? If you have configured the dbname, user and pass at the top of config.php, that is all you need and it must work. If the connection with those credentials fails, then the phonebook will try to read /etc/amportal.conf and use whatever database name and credentials are set there.
If you use freepbx, you should not create a database and do nothing, as it will be auto handled by the application itself. Only if you are not using freepbx you have to create the database/table and setup the correct credentials in config.php
