👀 Views: 460 💬 Answers: 1 📅 Created: 2025-06-17

django bulk-create integrityerror postgresql Python

I'm maintaining legacy code that I am working with an `IntegrityError` when trying to bulk create related models in Django, specifically when using the `bulk_create` method. The setup involves two models, `Author` and `Book`, where each book must have a valid author. Here’s a simplified version of my code: ```python from django.db import models, IntegrityError class Author(models.Model): name = models.CharField(max_length=100) class Book(models.Model): title = models.CharField(max_length=200) author = models.ForeignKey(Author, on_delete=models.CASCADE) # Creating authors authors = [Author(name='Author 1'), Author(name='Author 2')] Author.objects.bulk_create(authors) # Attempting to create books books = [Book(title='Book 1', author=authors[0]), Book(title='Book 2', author=authors[1])] try: Book.objects.bulk_create(books) except IntegrityError as e: print(f'IntegrityError: {e}') ``` I've confirmed that both authors are created successfully since I check the database afterwards. However, when I run the `bulk_create` for the books, I receive an `IntegrityError` with the message `null value in column "author_id" violates not-null constraint`. This is perplexing because I ensure that the `author` field is being set with valid `Author` instances from the previous bulk create. I've tried using `refresh_from_db()` on the `authors` to see if they’re updated correctly post creation, and I also verified that the `Author` objects exist in the database using `Author.objects.all()`. I even stepped through the code with a debugger to ensure that the `author` references are correct before the `bulk_create`. I’m using Django 3.2 with PostgreSQL as the database backend. Is there something I'm missing when working with `bulk_create`, especially with related fields? Any insights or suggestions would be appreciated! I'm developing on Ubuntu 20.04 with Python. Could this be a known issue? Cheers for any assistance!