Django 4.2: How to handle multiple related model instances in a serializer correctly?
Hey everyone, I'm running into an issue that's driving me crazy. I'm working with an scenario with Django 4.2 while trying to serialize a nested structure of related models. I have two models, `Author` and `Book`, where `Author` can have multiple `Book` instances. My goal is to create a serializer for `Author` that includes a nested representation of the related `Book` instances. However, when I serialize an `Author` instance, the related books don't appear in the output, and I'm getting an empty list for the books. Here's a simplified version of the models and serializers I've set up: ```python from django.db import models from rest_framework import serializers class Author(models.Model): name = models.CharField(max_length=100) class Book(models.Model): title = models.CharField(max_length=200) author = models.ForeignKey(Author, related_name='books', on_delete=models.CASCADE) class BookSerializer(serializers.ModelSerializer): class Meta: model = Book fields = ['title'] class AuthorSerializer(serializers.ModelSerializer): books = BookSerializer(many=True, read_only=True) class Meta: model = Author fields = ['name', 'books'] ``` When I call the `AuthorSerializer` with an `Author` instance that has associated books, the output looks like this: ```json { "name": "John Doe", "books": [] } ``` I've double-checked that the `Author` instance has related `Book` instances, but they still aren’t appearing in the serialized output. I suspect it might be due to how the related names or the ForeignKey are set up, but I need to figure out what's wrong. I've also tried using `prefetch_related` when fetching the `Author` instance in my view, but that didn’t solve the question either. Here’s how I'm retrieving the author in my view: ```python from rest_framework.views import APIView from rest_framework.response import Response class AuthorDetailView(APIView): def get(self, request, pk): author = Author.objects.prefetch_related('books').get(pk=pk) serializer = AuthorSerializer(author) return Response(serializer.data) ``` Any insights on why the nested `books` are not appearing would be greatly appreciated! Thanks, I really appreciate it! Any suggestions would be helpful.