Django 4.1: implementing Filtering Related Models with Complex Conditions in QuerySet
I'm testing a new approach and I'm performance testing and I've been struggling with this for a few days now and could really use some help... I'm working on a Django 4.1 application where I need to filter a queryset of `Book` objects based on conditions from a related `Author` model. The `Book` model has a ForeignKey to the `Author` model. What I want to achieve is to filter books that are written by authors with a `rating` greater than 4 and an `active` status. Here's a simplified version of my models: ```python class Author(models.Model): name = models.CharField(max_length=100) rating = models.FloatField() active = models.BooleanField(default=True) class Book(models.Model): title = models.CharField(max_length=200) author = models.ForeignKey(Author, on_delete=models.CASCADE) ``` My initial attempt at fetching the filtered books looks something like this: ```python filtered_books = Book.objects.filter(author__rating__gt=4, author__active=True) ``` However, this returns an empty queryset, even though there are authors that meet these criteria. When I check the database, I can confirm that there are authors with a `rating` greater than 4 that are also marked as `active`. To debug, I tried printing the SQL query generated by this queryset: ```python print(filtered_books.query) ``` The SQL looks accurate, but it returns no results. Additionally, I tried using `distinct()` and even looked into whether the related model (`Author`) had any entries that could be causing this scenario: ```python print(Author.objects.filter(rating__gt=4, active=True).count()) ``` This returns a count greater than zero, confirming that there are valid authors that should be linking to books. I also verified that the ForeignKey relationship is correctly set up and that the data is consistent. Is there something I'm missing in how Django processes these filters? Or is there a known caveat with filtering across relations that might lead to an empty result like this? Any insights would be greatly appreciated! My development environment is Windows. Has anyone else encountered this? Is there a better approach? I'm on macOS using the latest version of Python. I recently upgraded to Python 3.11. How would you solve this?