用 django form 提交表单怎么批量对 m2m 字段进行保存啊？？

[myung]

用 django form 提交表单怎么批量对 m2m 字段进行保存啊？？

ValueError: "<OrderShipping: OS-180623085540>" needs to have a value for field "id" before this many-to-many relationship can be used.

class OrderGoodsInfo(models.Model):
    ...
....

class OrderShipping(models.Model):
    order = models.ManyToManyField(OrderGoodsInfo, blank=True, verbose_name="物流 ID")
....

views.py

container_orders_id = [] 
for order in container_obj.orders.all():
    container_orders_id.append(order.id)
order_goods = OrderGoodsInfo.objects.filter(id__in=container_orders_id)
order_shipping = OrderShipping(user=request.user)
form = OrdershippingForm(request.POST, instance=order_shipping) 
if form.is_valid():
   osp = form.save(commit=False)
   osp.order.add(*order_goods)
   osp.save()

写成这样不行啊。。。。