I have a Business model and Order model. Businesses can order furniture in our website. A user creates an account and makes an order. Since he is a new user, he is not associated to any Business. In the order form, he will give the information about his business and some information related to current order. A new Business record and Order record will be created with the given info. There’s a foreign key for Business in Order table.

If he wants to create a second order, since he has already a business, he will have the business info pre-filled in his form. When he gives the order data and submits, backend won’t create a new Business record. It only creates Order record and store the Business reference.

How do I achieve this in single endpoint to create update and retrieve?

# serializers.py

import time

class BusinessSerializer(serializers.ModelSerializer):
    class Meta:
        model = Business
        fields = '__all__'
        
    def create(self, validated_data):
        timestamp = int(time.time())
        random_number = random.randint(100,999)
        validated_data['code'] = f'BUSINESS-{timestamp}'
        validated_data['status'] = 'CREATED'
        return super().create(validated_data)

class OrderSerializer(serializers.ModelSerializer):
    class Meta:
        model = Order
        fields = '__all__'
        
    def create(self, validated_data):
        timestamp = int(time.time())
        random_number = random.randint(100,999)
        validated_data['code'] = f'ORDER-{timestamp}'
        validated_data['status'] = 'CREATED'
        return super().create(validated_data)

# views.py

class BusinessOrderAPIView(generics.CreateAPIView):
    permission_classes = [IsAuthenticated]
    queryset = Order.objects.all()
    serializer_class = OrderSerializer

    def perform_create(self, serializer):

        business_data = self.request.data.get('business', {})
        business_id = business.get('id')
        if business_id:
            try:
                business = Business.objects.get(pk=business_id)
            except Business.DoesNotExist:
                business = Business.objects.create()
            business.name = business_data.get('name')
            business.website = business_data.get('website')
            business.address = business_data.get('address')
            business.city = business_data.get('city')
            business.state = business_data.get('state')
            business.country = business_data.get('country')
            business.save()

            order = serializer.save(business=business.pk)

This is how my request would look

{
    
    "chairs": 3,
    "tables": 1,
    "delivery_type": "ONE_DAY",
    "payment_type": "CASH_ON_DELIVERY",
    "business": {
        "name": "Vin.AI",
        "website": "https://lol.com",
        "address": "My street",
        "city": "Gotham City",
        "state": "New York",
        "country": "USA",
    }
}