一对多中的未定义属性错误

Question

我正在尝试制作一个应用程序，您可以在其中管理办公材料、发票等。所以我的订单有很多材料和一张发票。

我的材料表有：

id | name | count_all | count_current | price_unit

我的订单表有：

id | count_order | material_id | invoice_id

我的发票表有：

id | number | inc_date | scan_name | sum

我的材料模型看起来像：

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Material extends Model
{
    public function order(){
        return $this->belongsTo('Order', 'material_id');
    }
    public function expenditure(){
        return $this->belongsTo('Expenditure');
    }
    protected $fillable = [
        'name', 'count_all', 'count_current', 'price_unit',
    ];
}

我的订单模型如下所示：

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Order extends Model
{
    public function invoice(){
        return $this->hasOne('App\Invoice');
    }

    public function material(){
        return $this->hasMany('App\Material');
    }

    protected $fillable = [
        'count_order',
    ];
}

我的 OrderController 看起来像：

<?php

namespace App\Http\Controllers;

use App\order;
use Illuminate\Http\Request;
use DB;
use App\Http\Controllers\Controller;

class orderController extends Controller
{
    /**
     * Show a list of all of the application's orders.
     *
     * @return Response
     */
    public function show()
    {
        $orders = DB::table('orders')->get();

        return view('order', ['orders' => $orders]);
    }

    public function insert(Request $request){

        $order = new order;

        $order->count_order = $request->count_order;

        $order->save();
        return redirect('/order');
    }

    public function edit(order $order){

        return view('edit_order', compact('order'));   
    }

    public function update(Request $request, order $order){
        if(isset($_POST['delete'])){
            $order->delete();
            return redirect('/order');
        }
        else{
            $order->count_order = $request->count_order;

            $order->save();
            return redirect('/order');
       }
    }
}

因此，当尝试访问数据库时，我将在我的路线中使用功能“显示”。

还有我的一块“引起问题”的刀片：

<tbody>
    @foreach($orders as $order)
    <tr>
        <td>{{$order->id}}</td>
        <td>{{$order->material->name}}</td> //this is causing the Undefined property problem when trying to display material name instead of id
        <td>{{$order->invoice_id}}</td> //this should look similar to the one above but since it doesn't work I didn't change it
        <td>{{$order->count_order}}</td>
        <td>    
            <form action="/order/{{$order->id}}">
                <button type="submit" name="edit" class="btn btn-primary">Edycja zamówienia</button>
                {{ csrf_field() }}
            </form>
        </td>
    </tr>
    @endforeach
    </tbody>

因此，当我尝试在刀片中显示材质名称时（如上），它返回以下错误：

Undefined property: stdClass::$materials (View: C:\xampp\htdocs\laravel\petition_app\resources\views\order.blade.php)

Answer 1

您需要使用从order 到material 的belongsTo() 关系。将您的 relationship 更改为：

public function material(){
    return $this->belongsTo('App\Material','material_id');
}

您正在使用query builder，您需要使用laravel eloquent 访问relationship 模型数据。更改您的控制器logic 代码如下：

$orders = Order::all();