Django 4.1 - Trouble with Custom Manager Filtering on Related Fields
I'm working with an scenario with a custom model manager in Django 4.1 where I want to filter related records based on a field in the related model. I have two models: `Author` and `Book`, where `Book` has a foreign key to `Author`. The goal is to create a custom manager for `Book` that allows filtering books by the author's `country`. Here's how my models are defined: ```python from django.db import models class Author(models.Model): name = models.CharField(max_length=100) country = models.CharField(max_length=50) class BookQuerySet(models.QuerySet): def by_author_country(self, country): return self.filter(author__country=country) class Book(models.Model): title = models.CharField(max_length=200) author = models.ForeignKey(Author, on_delete=models.CASCADE) objects = BookQuerySet.as_manager() ``` When I try to use this manager method in my view like so: ```python books_in_uk = Book.objects.by_author_country('UK') ``` I expected to get a queryset of books written by authors from the UK. However, I receive an empty queryset. Debugging this, I confirmed that there are indeed authors from the UK with several books in the database. When I run the following query directly in the Django shell: ```python Book.objects.filter(author__country='UK') ``` It returns the expected results. This makes me wonder if there’s an scenario with the custom manager or the way I’m applying the filter in my view. I've also checked for any typos in the field names and everything seems correct. Is there something I'm missing with how Django handles custom managers, or could there be an scenario with the queryset caching? Any insights or suggestions would be greatly appreciated!