将用户分配给Laravel关系中的任何商店?

在laravel中，我有3张桌子

In laravel, I have 3 table

 User // for Authentication and Create Another User Once logged in
 Expense
 Shop

我的目的-我希望用户可以注册并且还可以在他们登录时创建另一个用户，并且assign用户可以根据需要登录到另一个Shop.

My Purpose- I want user can register and Also, can create another user when they logged in And Can assign user to another Shop as they want..

并且只有User in the Same Shop可以看到他们的Expense ..

And Only User in the Same Shop Can see their Expense..

//我的User表格

<pre>
   Schema::create('users', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->unsignedBigInteger('shop_id')->nullable();
        $table->unsignedBigInteger('user_id')->nullable();
        $table->string('name');
        $table->string('email')->unique();
        $table->timestamp('email_verified_at')->nullable();
        $table->string('password');
        $table->rememberToken();
        $table->timestamps();
    });
</pre>

//我的Expense表格

<pre>
    Schema::create('expenses', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->unsignedBigInteger('user_id');
        $table->date('date');
        $table->string('description');
        $table->double('amount');
        $table->timestamps();
        $table->foreign('user_id')->references('id')->on('users');
    });
</pre>

//我的Shop表格

<pre>
     Schema::create('shops', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->unsignedBigInteger('expense_id')->nullable();
        $table->unsignedBigInteger('user_id');
        $table->string('name');
        $table->string('description');
        $table->timestamps();
        $table->foreign('expense_id')->references('id')->on('expenses');         
        $table->foreign('user_id')->references('id')->on('users');         
    });
</pre>

//我的用户模型

<pre>
   public function expense()
    {
        return $this->hasMany(\App\Expense::class);
    }


    public function shop()
    {
        return $this->hasMany(\App\Shop::class, 'user_id');
    }
</pre>

//我的费用模型

<pre>
class Expense extends Model
{
    protected $fillable = ['date', 'description', 'amount', 'user_id', 'shop_id'];

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

}
</pre>

//我的商店型号

<pre>
class Shop extends Model
{
    protected $fillable = ['name', 'description', 'expense_id', 'shop_id'];

    public function user()
    {
        return $this->belongsTo(\App\User::class, 'user_id');
    }

}
</pre>

//费用控制员

<pre>
 public function index(Request $request)
    {
        $expense = Expense::with(['user'])->get();

        return ExpenseResource::collection($expense);

        // dd(auth()->user());
    }

    public function create(Request $request)
    {
        $request->validate([
            'date' => 'required',
            'description' => 'required',
            'amount' => 'required',

        ]);

        $expense = new Expense();
        $expense->user_id = auth()->user()->id;
        $expense->date = $request->date;
        $expense->description = $request->description;
        $expense->amount = $request->amount;
        $expense->save();

        return new ExpenseResource($expense);
    }
</pre>

//在我的UserController中

// in My UserController

<pre>
public function index()
    {
        $users = User::all();
        $shops = Shop::all();
        return view('user', compact('users', 'shops'));
        // return UserResource::collection($users);
    }

    public function create(Request $request)
    {
        $request->validate([
            'name' => 'required',
            'email' => 'required',
            'password' => 'required',
        ]);

        $user = new user();
        $user->user_id = auth()->user()->id;
        $user->name = $request->name;
        $user->email = $request->email;
        $user->password = bcrypt($request->password);
        $user->save();

        return new UserResource($user);
    }
</pre>

有道理吗?

任何想法，谢谢.