Django 4.1: How to handle related-field queries returning empty queryset when filtering by ManyToMany fields?
I'm learning this framework and After trying multiple solutions online, I still can't figure this out. I'm working on a Django 4.1 project where I have two models, `Author` and `Book`, with a ManyToMany relationship. I want to filter `Book` instances based on a specific `Author`, but the queryset is unexpectedly empty. Here's a simplified version of my models: ```python class Author(models.Model): name = models.CharField(max_length=100) class Book(models.Model): title = models.CharField(max_length=200) authors = models.ManyToManyField(Author) ``` I tried running the following query to get books written by a specific author: ```python author_id = 1 # assuming there is an author with this ID books = Book.objects.filter(authors__id=author_id) print(books) ``` To my surprise, this returns an empty queryset, even though I know there are books associated with that author. I checked the database and confirmed that the relationship is set up correctly and that there are indeed books linked to the author with ID 1. I also tried using the `distinct()` method to see if it would make a difference, like this: ```python books = Book.objects.filter(authors__id=author_id).distinct() ``` Still, the result is empty. I double-checked that I'm querying the correct database and that there are no typos in the model or field names. I’ve even cleared the migrations and re-applied them to ensure the schema is correct. Is there something I'm missing, or is there a specific way to handle ManyToMany filtering in Django 4.1 that I’m not aware of? Any help would be greatly appreciated! What's the best practice here? Any ideas what could be causing this?