Просто пример работы

pdoFeach.php

$pdo = $modx->getService('pdoFetch');
$pdo->setConfig(array(
    'class' => 'modResource',
    'loadModels' => 'minishop2',
    'class_key' => 'msProduct',
    'parents' => '9920',
    'leftJoin' => array(
        'Data' => array(
            'class' => 'msProductData',
            'on' => 'modResource.id = Data.id',
        ),
        'Option' => array(
                'class' => 'msProductOption',
                'on' => 'modResource.id = Option.product_id'
            )
    ),
    'where' => array('Option.key' => 'mstime'),
    'select' => array(
        'modResource' => 'id, pagetitle',
        'Data' => 'price',
        'Option' => 'value'
    ),
    'return' => 'array'
));
echo $pdo->run();