public static function create($conn = null, $class = null) { $q = new ProductQuery($conn); $q->addSelect('p.id, p.reference, p.description, p.price')->addSelect($q->quantity_col)->addSelect($q->sold_col)->from("Product p, p.Items i, i.Common inv")->orderBy('p.reference asc')->groupBy('p.id'); // echo $q->getSqlQuery(); return $q; }