CodexBloom - Programming Q&A Platform

Django Rest Framework - 'Field required' scenarios when using serializers with nested relations

👀 Views: 3 💬 Answers: 1 📅 Created: 2025-06-08
django django-rest-framework serializers Python

I'm trying to debug I'm not sure how to approach I'm trying to configure I'm working with Django Rest Framework (DRF) version 3.13.1 and trying to serialize a model that has a nested relation to another model. My main model, `Book`, has a foreign key to another model, `Author`. When I try to create a new `Book` instance through the API, I receive a `{'author': ['This field is required.']}` behavior, even though I am including the author field in my request payload. Here’s the structure of my models: ```python class Author(models.Model): name = models.CharField(max_length=100) email = models.EmailField() class Book(models.Model): title = models.CharField(max_length=200) author = models.ForeignKey(Author, on_delete=models.CASCADE) ``` And here’s my serializer for the `Book` model: ```python from rest_framework import serializers class AuthorSerializer(serializers.ModelSerializer): class Meta: model = Author fields = ['id', 'name', 'email'] class BookSerializer(serializers.ModelSerializer): author = AuthorSerializer() class Meta: model = Book fields = ['id', 'title', 'author'] ``` When I send the following JSON payload to create a new book: ```json { "title": "New Book Title", "author": { "name": "John Doe", "email": "john@example.com" } } ``` I get the behavior mentioned above. I thought the nested serializer would handle the author creation automatically. What am I missing? I've tried overriding the `create` method in `BookSerializer` to handle the nested author, but that hasn’t solved the scenario either. Here’s what I tried: ```python class BookSerializer(serializers.ModelSerializer): author = AuthorSerializer() class Meta: model = Book fields = ['id', 'title', 'author'] def create(self, validated_data): author_data = validated_data.pop('author') author = Author.objects.create(**author_data) book = Book.objects.create(author=author, **validated_data) return book ``` However, I still face the same `Field required` behavior. Can someone guide to understand why this is happening and how to properly handle nested serializers in DRF? This is part of a larger web app I'm building. Thanks in advance! This is part of a larger application I'm building. I'm working in a CentOS environment. Could someone point me to the right documentation? I recently upgraded to Python 3.10. Any help would be greatly appreciated!