我定义了Model/User.php和Model/Cart.php之间的1-n关系，第一个是Model/User.php，第二个是Controller中的checkoutPost函数。

型号

namespace App\Models;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
use Laravel\Sanctum\HasApiTokens;

class User extends Authenticatable implements MustVerifyEmail
{
    use HasApiTokens, HasFactory, Notifiable;

    protected $table = 'users';
    protected $guards = 'users';
    protected $fillable = [
        'username',
        'email',
        'password',
        'email_verified_at'
    ];

    protected $hidden = [
        'password',
        'remember_token'
    ];

    protected $casts = [
        'email_verified_at' => 'datetime',
        'password' => 'hashed',
    ];

    public function carts(){
        return $this->hasMany(Cart::class,'users_id','id');
    }
}

字符串

控制器

public function checkoutPost(Request $request){
        $user = Auth::user();

        $message = [ 
            'required' => ':attribute không được bỏ trống',
            'min' => ':attribute phải lớn hơn 4 kí tự', // this is my message but in different language, dont worry about it
        ];

        $data = $request->validate([
            'first_name'=>'required|min:3',
            'last_name'=>'required',
            'email'=>'required|email',
            'phone'=>'required|min:9',
            'address'=>'required',
            'payment_method'=>'required',
        ], $message);

        $data = $request->only('first_name','last_name','email','phone','address','payment_method');
        $data['users_id'] = $user->id;

        $order = Order::create($data);

        $user->carts->each(function ($cart) use ($order) {
            OrderDetail::create([
                'order_id' => $order->id,   
                'product_id' => $cart->product_id,  
                'price' => $cart->price,    
                'quantity' => $cart->quantity
            ]);
            $cart->delete(); 
        });                             
    
        return redirect()->route('order.checkout');      
    }
}

型
它导致这行$user->carts->each(function ($cart) use ($order)中的错误
我正在我的电子商务项目中执行Checkout过程。代码对我来说似乎是正确的，但我一直收到错误消息。此外，数据库中确实存在购物车数据。