Django 4.1: Issues with Custom Model Managers Returning Unexpected QuerySets
I've spent hours debugging this and I'm performance testing and I've searched everywhere and can't find a clear answer. I'm encountering a problem with a custom model manager in Django 4.1 that is returning unexpected QuerySets when using it in a filter context. I've defined a custom manager for my `Product` model that should filter products based on their availability, but when I call it in a view, it seems to include products that are marked as unavailable. Here’s the model and manager setup: ```python from django.db import models class ProductQuerySet(models.QuerySet): def available(self): return self.filter(is_available=True) class ProductManager(models.Manager): def get_queryset(self): return ProductQuerySet(self.model, using=self._db) def available(self): return self.get_queryset().available() class Product(models.Model): name = models.CharField(max_length=100) is_available = models.BooleanField(default=False) objects = ProductManager() ``` In my view, I'm trying to retrieve all available products: ```python from django.shortcuts import render from .models import Product def product_list(request): products = Product.objects.available() return render(request, 'product_list.html', {'products': products}) ``` However, the `products` queryset includes items where `is_available` is set to `False`. I've double-checked the database entries, and they are correctly set. I also ran a raw SQL query directly against the database and confirmed the results are as expected. I initially thought it might be related to how I'm chaining the methods or the queryset handling, but everything seems to be in order. When I print out the SQL query that Django generates, I see it correctly references the `is_available` field, but the results still include unavailable products. I’ve also tried overriding the `filter()` method within the custom manager, but the issue persists. Here's the generated SQL from `QuerySet`: ```sql SELECT * FROM myapp_product WHERE is_available = TRUE; ``` Is there something I’m missing in the context of how Django manages querysets or perhaps an issue with how the manager is set up? Any insights or suggestions would be greatly appreciated. I'm working on a API that needs to handle this. What am I doing wrong? What's the best practice here? What's the correct way to implement this?