<?php
 
define('MODX_CORE_PATH', '/path/to/revo/core/');
define('MODX_CONFIG_KEY','config');
require_once MODX_CORE_PATH . 'model/modx/modx.class.php';
 
// Criteria for foreign Database
$host = 'localhost';
$username = 'your_username';
$password = 'your_password';
$dbname = 'your_database';
$port = 3306;
$charset = 'utf-8';
 
$dsn = "mysql:host=$host;dbname=$dbname;port=$port;charset=$charset";
$xpdo = new xPDO($dsn, $username, $password);
 
// Test your connection
echo $o = ($xpdo->connect()) ? 'Connected' : 'Not Connected';
 
// Issue queries against the foreign database:
$results = $xpdo->query("SELECT id FROM some_table"); 

.....

etc.