在 Laravel 中调用 int 上的成员函数 count()？

Question

我要统计本月新创建的学生总数和本月在线学生的数量

public function index () 
  {
     $month = Carbon::now()->month;
     $members = Member::getStudents();
     $saleareas = Member::getSaleAreas();
     Order::getTotalCardOnSaleAreas($saleareas);
     foreach ($members as $member) {
        $newstudent = $member->created_at->month;
        $online = $member->updated_at->month;
        if($month == $newstudent){
            $members = $members->count();
        }
        if($month == $online){
            $onl= $members->count(); // error           
        }
        $orders = Order::where('member_id',$member->id)->get();
        foreach ($orders as $order) {
            $neworder = $order->created_at->month;
            if($month == $neworder && $order->status = 'active'){
                $orders = $orders->count();
            };
        }
     }
      return view('admin.dashboard.index', compact('members','orders','onl','saleareas'));
        }

出现错误：调用 int 上的成员函数 count()

Answer 1

因为第一个 if，

if($month == $newstudent){
            $members = $members->count(); //here, the $members changed to an int
}

然后您尝试计算现在为整数的 $members，因此您会收到 Call to a member function count() on int 错误。

我认为你可以这样计算数据：

$total = count(DB::select(DB::raw("Select * from table where *put your condition here* ")));