to_field Django custom user model in admin, relation “auth_user” does not exist



programmingerror at/admin/login/ (4)

I have a custom user model as below:

class User(AbstractUser):
    subscribe_newsletters = models.BooleanField(default=True)
    old_id = models.IntegerField(null=True, blank=True)
    old_source = models.CharField(max_length=25, null=True, blank=True)

And using the builtin UserAdmin

admin.site.register(User, UserAdmin)

While editing the user record works fine, but when I add a user, I get the following error

Exception Value: 
relation "auth_user" does not exist
LINE 1: ...user"."is_active", "auth_user"."date_joined" FROM "auth_user...

Answer #1

After some digging around I found this

https://docs.djangoproject.com/en/1.5/topics/auth/customizing/#custom-users-and-the-built-in-auth-forms

The culprit is a function clean_username inside UserCreationForm inside django.contrib.auth.forms.py. A few tickets have been created, but apparently the maintainers don't think it's a defect:

https://code.djangoproject.com/ticket/20188

https://code.djangoproject.com/ticket/20086

def clean_username(self):
        # Since User.username is unique, this check is redundant,
        # but it sets a nicer error message than the ORM. See #13147.
        username = self.cleaned_data["username"]
        try:
            User._default_manager.get(username=username)
        except User.DoesNotExist:
            return username
        raise forms.ValidationError(self.error_messages['duplicate_username'])

The User in this file is directly referencing to the builtin user model.

To fix it, I created my custom forms

from models import User #you can use get_user_model
from django.contrib.auth.forms import UserCreationForm
from django.contrib.auth.admin import UserAdmin
from django.contrib.auth import forms

class MyUserCreationForm(UserCreationForm):
    def clean_username(self):
        # Since User.username is unique, this check is redundant,
        # but it sets a nicer error message than the ORM. See #13147.
        username = self.cleaned_data["username"]
        try:
            User._default_manager.get(username=username)
        except User.DoesNotExist:
            return username
        raise forms.ValidationError(self.error_messages['duplicate_username'])

    class Meta(UserCreationForm.Meta):
        model = User

class MyUserAdmin(UserAdmin):  
    add_form = MyUserCreationForm   

admin.site.register(User,MyUserAdmin)

Or you can try monkey patching the original UserCreationForm to replace the User variable.



Answer #3

Django 1.8

If your app is not yet using migrations then this could also be the problem, as contrib.auth uses them. Enabling migrations for my app solved it for me.

$ ./manage.py makemigrations <my_app>
$ ./manage.py migrate

Answer #4

I had to:

  1. delete the database
  2. create a new database
  3. delete all migrations from all models
  4. make migrations anew
  5. migrate

It was double annoying because I had to do it on local and remote server. I tried just deleting migrations or deleting the database but then git would push/pull the old migrations and messed everything up.

P.S. This bug initially arose because I ran the migrations before adding AUTH_USER_MODEL = 'customauth.MyUser' to the settings.py file, which is not version controlled.





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