В чем ошибка xpdo set update?

public function prepareListQueryBeforeCount(xPDOQuery $c) {
           $c = parent::prepareListQueryBeforeCount($c);

          $c->select(array(
                     'lfvideoItem.id',
                     'c.mashine',

          ));

             $c->innerJoin('LfvideoStatus', 'c','lfvideoItem.id = c.idjob');

          $c->command('update');


          $c->set(array(
                'c.mashine' => '-1'
            ));

          $c->where(array(
                'status' => '-1'
            ));

          $c->prepare();
          print $c->toSQL();
          $c->stmt->execute();

          print_r($c->stmt->errorInfo());
			

        return $c;
    }

UPDATE `modx_lfvideo_items` JOIN `modx_lfvideo_status` `c` ON lfvideoItem.id = c.idjob WHERE `modx_lfvideo_items`.`status` = -1 Array
(
    [0] => 42000
    [1] => 1064
    [2] => You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE `modx_lfvideo_items`.`status` = -1' at line 1