如何访问Laravel中的Pivot？

I'm having problems accessing the Pivot relationship.

 #relations: array:1 [
        "orders_material" => Collection {#250
          #items: []
        }
      ]

I want to get the orders_material that have pivot values null

This is the query :

 $material = Material::with(['orders_material' => function($query)  use ($begin_date, $end_date, $begin_hour, $hour_final) 
     {
        $query->whereBetween('Orders_has_Material.date_begin',[$begin_date, $end_date])
        ->whereBetween('Orders_has_Material.date_final',[$begin_date, $end_date])
        ->where('Orders_has_Material.Material_id', null)
        ->where('Orders_has_Material.Orders_id', null);
      }])

    ->get();

    dd($material);

public function orders_material()
     {
         return $this->belongsToMany('App\Orders', 'Orders_has_Material', 'Material_id', 'Orders_id');
     }

First of all, as I see here u have many columns in ur pivot table like date_begin and date_final so here u need to edit ur relationship models like this :

public function orders_material()
 {
     return $this->belongsToMany('App\Orders', 'Orders_has_Material', 'Material_id', 'Orders_id')->withPivot('date_begin', 'date_final', 'column3');
 }

and to access to them just u need to get $material of orders or the inverse.

which means, as u get the $material in ur query, i think to want to access to the orders related to that $material and show up some information inside ur pivot table. u can access to them like this (if ur relationship models are correct of course):

foreach($material->orders as $order)
{
   echo $order->pivot->date_begin; 
   echo $order->pivot->date_final; 
}

for more information read the doc many to many laravel with pivot table