👀 Views: 0 💬 Answers: 1 📅 Created: 2025-07-05

django bulk-update integrityerror models Python

I'm experimenting with I've hit a wall trying to I tried several approaches but none seem to work... I'm working with an `IntegrityError` when attempting to perform a bulk update on related models in my Django 4.1 application. I have a `Book` model that has a foreign key relationship with an `Author` model. Here's how my models are defined: ```python class Author(models.Model): name = models.CharField(max_length=100) email = models.EmailField() class Book(models.Model): title = models.CharField(max_length=200) author = models.ForeignKey(Author, on_delete=models.CASCADE, related_name='books') published_date = models.DateField() ``` I initially tried updating the `published_date` of multiple books related to a specific author using `bulk_update`, but it seems like I'm getting a `django.db.utils.IntegrityError: null value in column "author_id" violates not-null constraint`. Here's the code that I'm using: ```python from django.db import transaction with transaction.atomic(): books_to_update = Book.objects.filter(author__name='John Doe') for book in books_to_update: book.published_date = '2023-10-01' Book.objects.bulk_update(books_to_update, ['published_date']) ``` I thought `bulk_update` should handle the foreign key references correctly, but it seems like it loses the foreign key in the process. I also tried updating the objects in a loop instead of using `bulk_update`, which works fine, but it's significantly slower for large datasets. Is there a specific reason why `bulk_update` would lose the foreign key reference during this operation? Is there a better approach to perform bulk updates while maintaining integrity? Any insights would be appreciated! Any ideas what could be causing this? How would you solve this? This is part of a larger microservice I'm building. This is for a REST API running on Windows 10. Any feedback is welcome!