Ajax: can't connect to XPDO

<?php
 
define('MODX_CORE_PATH', '/var/www/html/raf/core/');
define('MODX_CONFIG_KEY','config');

require_once MODX_CORE_PATH . 'model/modx/modx.class.php';
 
$host = 'localhost';
$username = 'admin';
$password = 'p4ssword';
$dbname = 'dbase1';
$charset = 'utf-8';
 
$dsn = "mysql:host=$host;dbname=$dbname;charset=$charset";
$xpdo = new xPDO($dsn, $username, $password);
 
echo $o = ($xpdo->connect()) ? 'Connected' : 'Not Connected';
    
$results = $xpdo->query("SELECT id FROM some_table");
$recordCount = $results->rowCount();
print $recordCount;