Services\GpService::delete PHP Method

    public function delete($id)
    {
        if (!($gp = $this->model->findByPk($id))) {
            throw new NotFound("GP with ID '{$id}' not found");
        }
        $crit = new \CDbCriteria();
        $crit->compare('gp_id', $id);
        \Patient::model()->updateAll(array('gp_id' => null), $crit);
        $gp->delete();
    }