Поиск всех производителей в подкаталоге

subcategory_vendors.php

<?php
$parent = 12791;
$parents = array_merge([$parent], $modx->getChildIds($parent, 10, ['context' => 'web']));
$template = [28];

$pdo = $modx->getService('pdoFetch');
$results = $pdo->getCollection('msProduct', [], [
        'leftJoin' => [
            'msProductData' => [
                'class' => 'msProductData',
                'on' => 'msProduct.id = msProductData.id'
            ],
            'msVendor' => [
                'class' => 'msVendor',
                'on' => 'msProductData.vendor = msVendor.id'
            ]
        ],
        'where' => [
            'msProduct.parent:IN' => $parents,
            'msProduct.template:IN' => $template
        ],
        'groupby' => 'msVendor.name',
        'select' => [
            'msProduct' => 'id',
            'msProductData' => 'vendor',
            'msVendor' => 'msVendor.name AS vendor_name',
        ],
    ]
);
echo count($results);
foreach ($results as $result)
{
    print_r($result);
}