Method getCategoriesByProducts

public static function getCategoriesByProducts($productsA)
{
    $productsS = '';
    $categories = '';
    if (!empty($productsA)) {
        $productsS = implode(',', $productsA);
        $db = Factory::getDBO();
        $query = ' SELECT pc.product_id, c.id, c.alias, c.title FROM #__phocacart_categories AS c' . ' LEFT JOIN #__phocacart_product_categories AS pc ON c.id = pc.category_id' . ' WHERE pc.product_id IN (' . $productsS . ')';
        $db->setQuery($query);
        $categories = $db->loadAssocList();
    }
    return $categories;
}