Django QuerySet not returning expected results when filtering with Q objects and related fields
I'm migrating some code and I'm attempting to set up I'm working on a Django project where I need to filter a queryset using `Q` objects for related fields, but I'm not getting the expected results. I have two models, `Author` and `Book`, where each `Book` has a foreign key to `Author`. My goal is to retrieve all books written by authors whose names contain 'John' or whose birth year is before 1980. Here's my current code snippet: ```python from django.db.models import Q results = Book.objects.filter(Q(author__name__icontains='John') | Q(author__birth_year__lt=1980)) ``` However, the output does not include any books by authors named 'John', even though I know there are some in the database. I also tried printing the generated SQL query using `str(results.query)` and it looks correct. To troubleshoot, I executed the same filtering criteria directly in the database and got the expected results. I confirmed that `author__name` and `author__birth_year` are valid fields and that the relationships are set up properly in the ORM. I've also checked for typos and verified that the queryset is not being modified elsewhere in my view before it's rendered. I am using Django version 4.0.3 and Python 3.9. I really need this filtering to work correctly; can anyone guide to understand why this might be happening? What am I doing wrong?