You can use the following php script which is used to test mysql database connection on your cpanel server.
<?php
$link = mysql_connect('db_host', 'db_username', 'db_password');
if (!$link)
{
die('Could not connect the database: ' . mysql_error());
}
echo 'Database Connected successfully';
mysql_close($link);
?>
db_host : Mostly used ‘localhost’ when you connect on the same server.
db_username : Use your test database username.
db_password : Use your test database password.
The above MySQL connection test script is using mysql_connect(); function which is designed to open a connection to a MySQL Server
That's All