This article shows how to use PHP to access a database from within OpenShift. In this case the PHP code is accessing the MySQL database within the same application.
function db_connect()
{
$db_username = getenv('OPENSHIFT_MYSQL_DB_USERNAME');
$db_password = getenv('OPENSHIFT_MYSQL_DB_PASSWORD');
$db_host = getenv('OPENSHIFT_MYSQL_DB_HOST') . ":" . getenv('OPENSHIFT_MYSQL_DB_PORT');
$db_name = "mydbname";
$conn = new mysqli($db_host, $db_username, $db_password, $db_name);
return $conn;
}
The above function should be called before you run any SQL commands.