How to set up double nested serializer in Django Rest Framework - django

Question

I am trying to figure out how to set up my nested serializers.
# models.py
class Product(models.Model):
sku = models.CharField()
product_name = models.CharField()
class Order(models.Model):
name = models.CharField()
address = models.CharField()
class OrderProduct(models.Model):
order = models.ForeignKey( Order )
product = models.ForeignKey( Product )
quantity = models.IntegerField()
So I want to have an api that can create an order in the form of the following:
{
"name" : "James",
"address" : "100 Main St",
"products" : [
{ "sku" : "1234", "quantity" : 1 }
]
}
I understand that I would need nest OrderProductSerializer inside OrderSerializer, but how do I implement it here when the "products" data use the field "sku" which is not found in the OrderProduct model. Do I do double-nesting? How does that look like?
# serializers.py
class OrderProductSerializer( serializers.ModelSerializer):
class Meta:
model = OrderProduct
exclude = ()
class OrderSerializer(serializers.ModelSerializer):
products = OrderProductsSerializer(many=True)
class Meta:
model = Order
exclude = ()

Answer 1

You are trying to implement Nested Serialize on reverse relationship. So, you have to explicitly provide the relationship name as the parameter to the serializer via source argument.
Try this
class OrderProductSerializer(serializers.ModelSerializer):
class Meta:
model = OrderProduct
fields = '__all__'
class OrderSerializer(serializers.ModelSerializer):
product = OrderProductSerializer(many=True, source='product_set')
class Meta:
model = Order
fields = '__all__'
For more info reffere these docs
1. DRF Nested Relationship
2. DRF-Reverse Realation
3. What is reverse-relationship in Django