数据库中有两个表，分别为一对多关系：主表(预约信息)：dbo.Reservation``` [ReservationID] [INT] IDENTITY(1,1) NOT NULL, [ReservationNo] [NVARCHAR](24) NOT  NULL,    ......```明细表（预约明细）：dbo.ReservationDetail``` [ReservationDetailID] [INT] IDENTITY(1,1) NOT NULL, [ReservationID] [INT] NOT NULL,                          --外键    ......```Model的代码如下：Reservation.php```<?phpnamespace App\Models;use Illuminate\Database\Eloquent\Model;class Reservation extends Model{    protected  $table = 'dbo.Reservation';    public function hasManyReservationDetails()    {        return $this->hasMany('App\Models\ReservationDetail', 'ReservationID', 'ReservationID');    ```ReservationDetail.php```<?phpnamespace App\Models;use Illuminate\Database\Eloquent\Model;class ReservationDetail extends Model{    protected  $table = 'dbo.ReservationDetail';    public function belongsToReservation()    {        return $this->belongsTo('App\Models\Reservation', 'ReservationID', 'ReservationDetailID');    ```在一个API的controller里面调用```<?phpnamespace App\Api\Controllers;use App\Models\Reservation;use App\Models\ReservationDetail;use App\Http\Requests;class ReservationController extends BaseController{    public function showByReservationNo($reservation_no)    {        $reservation_details = ReservationDetail::all()            ->belongsToReservation()            ->where('ReservationNo', '=', $reservation_no)            ->get();        return $reservation_details;    ```Laravel返回的错误信息如下：```  "message": "Method belongsToReservation does not exist.",  "status_code": 500,```请问这是什么原因，是不是namespace的问题？我希望实现的是用主表的某个条件关联去查询明细表，返回明细表的数据，查询的SQL语句如下：```SELECT ReservationDetail.*FROM ReservationDetailINNER JOIN Reservation ON Reservation.ReservationID = ReservationDetail.ReservationIDWHERE Reservation.ReservationNo = 'xxx'```请问各位大牛，问题出在什么地方？准确的语法应该怎么写？另一个问题是，如果希望返回的数据是将主表和明细表合并成一个对象返回，例如：```{  "ReservationID": "1",   "ReservationNo": "201601011000",   "ReservationDetails": [    {      "ReservationDetailID": "1",       "ReservationID": "1",     },     {      "ReservationDetailID": "2",       "ReservationID": "1",     }  ]}```关联查询应该怎么写？请各位大牛赐教，感激涕零！！！