Django filter on OneToOne field appending "_id" and failing

Question

In my Django application I have the following model:

class Provider(models.Model):
    user = models.OneToOneField(CustomUser, on_delete=models.CASCADE, primary_key=True)
    company = models.ForeignKey(Company, on_delete=models.CASCADE)

    def __str__(self):
        return str(self.user)

Note user is a OneToOneField to my CustomUser table and also the primary key of this table.

In views.py , I attempt to query this table with Provider.objects.filter(user=request.user) and get django.db.utils.OperationalError: (1054, "Unknown column 'appname_provider.user_id' in 'field list'") . Checking my MySql database, I see the columns are (user, company_id) . So why is Django adding "_id" to user when I try to filter?

My CustomUser model:

class CustomUser(AbstractUser):
    is_provider = models.BooleanField()
    is_admin = models.BooleanField()
    first_name = models.CharField(max_length=128)
    last_name = models.CharField(max_length=128)
    email = models.EmailField(unique=True)
    REQUIRED_FIELDS = ["is_provider", "email"]
    objects = CustomUserManager()

    def __str__(self):
        return str(self.username)

Answer 1

Here's how I solved this issue:

1. Undo all migrations: rm -rf appname/migrations/0* appname/__pycache__ and in mysql: DELETE FROM django_migrations;
2. Delete the Provider table in mysql: DROP TABLE appname_provider;
3. Recreate the Provider table in mysql with column user_id instead of user : CREATE TABLE appname_provider (user_id INT PRIMARY KEY, company_id INT);
4. Reset migrations for builtin apps: python manage.py migrate --fake
5. Make migrations for this app: python manage.py makemigrations appname
6. Fake run the migrations since all the tables are still in the database: python manage.py migrate --fake
7. I then needed to make company_id a foreign key because I hadn't done that in step 3, so in Provider I did company = models.IntegerField() , made and ran migrations, then set it back to company = models.ForeignKey(Company, on_delete=models.CASCADE) , made and ran migrations again. This is a bit hacky, but without this change back and forth, Django did not detect that it had to make company_id a foreign key.

Now Provider contains a column user_id in the database instead of user , so the query works! Note with this approach you lose any data in the Provider table, but the rest of the database is preserved. I got some of the steps from this answer: https://stackoverflow.com/a/29898483/7632019 .