如何使用Laravel合并多个表？

php artisan make:model UserOrder

use Illuminate\Database\Eloquent\Model;

class UserOrder extends Model
{
    protected $table = 'users_orders';

    public function users()
    {
        return $this->belongsTo(User::class);
    }

    public function orders()
    {
        return $this->belongsTo(Order::class);
    }
}

php artisan make:migration create_users_orders_table --create=users_orders

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateUsersOrdersTable extends Migration
{
    public function up()
    {
        Schema::create('users_orders', function (Blueprint $table) {
            $table->id();
            $table->unsignedBigInteger('user_id');
            $table->unsignedBigInteger('order_id');
            // 添加其他字段
            $table->timestamps();

            $table->foreign('user_id')->references('id')->on('users');
            $table->foreign('order_id')->references('id')->on('orders');
        });
    }

    public function down()
    {
        Schema::dropIfExists('users_orders');
    }
}

use App\Models\UserOrder;

class UserOrderController extends Controller
{
    public function mergeTables()
    {
        $users = User::all();
        $orders = Order::all();

        foreach ($users as $user) {
            foreach ($orders as $order) {
                UserOrder::create([
                    'user_id' => $user->id,
                    'order_id' => $order->id,
                    // 设置其他字段的值
                ]);
            }
        }

        return "Tables merged successfully!";
    }
}

use App\Http\Controllers\UserOrderController;

Route::get('/merge-tables', [UserOrderController::class, 'mergeTables']);