👀 Views: 62 💬 Answers: 1 📅 Created: 2025-08-28

django admin integrityerror Python

I'm upgrading from an older version and Could someone explain I'm having trouble with the Django admin when trying to save a model that has a foreign key relationship along with a unique constraint. I have two models, `Author` and `Book`, where `Book` has a foreign key to `Author` and a unique constraint on the `title` field. When I try to add a new `Book` through the Django admin interface, I receive an `IntegrityError` saying that the title must be unique, even though I'm using a different title for the new book. Here are the relevant model definitions: ```python from django.db import models class Author(models.Model): name = models.CharField(max_length=100) def __str__(self): return self.name class Book(models.Model): title = models.CharField(max_length=200, unique=True) author = models.ForeignKey(Author, on_delete=models.CASCADE) def __str__(self): return self.title ``` I've tried to ensure that each time I create a new `Book` in the admin, the `title` is indeed unique. However, I keep running into this behavior: ``` IntegrityError: UNIQUE constraint failed: app_book.title ``` I've also checked for any existing books with the same title in the database using the Django shell: ```python from app.models import Book Book.objects.filter(title='My Unique Title') ``` This returns an empty queryset, but when I try to create a new `Book` with that title in the admin, it raises the behavior again. I've also verified that the `title` field is indeed set to unique in the database schema. Is there any specific step I'm missing or something I should look into? I'm using Django 4.0.3. I'm on Ubuntu 20.04 using the latest version of Python. I'd love to hear your thoughts on this. I'm developing on Ubuntu 22.04 with Python. Thanks, I really appreciate it!