mongodb native query in thinkphp framework

php mongodb query

    public function test()
    {
        $u = D('User')->getCollection()->find(['$or'=>[['mobile'=>'13888888888'], ['name'=>'test1']]]);
        foreach ($u as $v) {
            json_out($v);
        }
        $u = D('User')->getCollection()->distinct('name');
        json_out($u);
    }