如何在Django REST中手动填充关系模型

Question

I'm still new to Django and DRF. I have 2 models (Policy and Rescue) and Rescue is related to Policy by the Foreign Key policy_id. I have no issue to POST a JSON message and get Policy populated with the request data by CreateView. However, the 2nd model Rescue needs be populated based on some calculations from the JSON data POSTed to the Policy. Rescue cannot be POSTed beforehand. I tried hard but had no clue to do so.

Is this something to do with nested serializer or something else?

I've tried to

Can I try this way: inside the class CreateView:

class CreateView(generics.CreateAPIView):

    def create(self, request, *args, **kwargs):
        my_serializer = self.get_serializer(data=request.data)
        ...
        # get a policy object based on 'policy_id' against serializer
        my_policy = Policy.objects.get(policy_id=my_serializer.data['policy_id'])
        ...
        ... # some calculations to work out a rescue id, and will be returned and saved.
        Rescue.objects.create(rescue_id='QD1234', policy=my_policy)

Answer 1

you can use a generic CreateAPIView and override the perform_create method.

def perform_create(self, serializer):
    my_policy = serializer.save()
    # you custom calculation for rescue_id
    rescue_obj = Rescue.objects.create(rescue_id='QD1234', policy=my_policy)

perform create method is documented here: https://www.django-rest-framework.org/api-guide/generic-views/#methods