Using email as username field in Django 1.5 custom User model results in FieldError

Question

I want to use an email field as the username field for my custom user model. I have the following custom User model subclassing Django's AbstractUser model:

class CustomUser(AbstractUser):     ....     email = models.EmailField(max_length=255, unique=True)      USERNAME_FIELD = 'email' 

But when I run

python manage.py sql myapp

I get the following error:

FieldError: Local field 'email' in class 'CustomUser' clashes with field of similar name from base class 'AbstractUser'

The reason I include my own email field in the first place is to add the unique=True option to it. otherwise I get:

myapp.customuser: The USERNAME_FIELD must be unique. Add unique=True to the field parameters.

Now, in respect to this: https://docs.djangoproject.com/en/1.5/topics/db/models/#field-name-hiding-is-not-permitted
How can I achieve this? (other then naming the field "user_email" or something like that instead)

Answer 1

Ian, thank you very much for the clever response :)

However, I've already "patched" me a solution.

Since AbstractUser also have a username field which is totaly unnecessary for me
I decided to create my "own" AbstractUser.

By subclassing AbstractBaseUser and PermissionsMixin I retain most of the User model built-in methods without adding any code.

I also took advantage of that opportunity to create a custom Manager to eliminate the use in username field all together:

from django.contrib.auth.models import AbstractBaseUser, PermissionsMixin, BaseUserManager  class CustomUser(AbstractBaseUser, PermissionsMixin):      ....      email = models.EmailField(max_length=255, unique=True)      first_name = ...      last_name = ...      is_active = ...      is_staff = ...      ....       objects = CustomUserManager()       USERNAME_FIELD = 'email'   class CustomUserManager(BaseUserManager):      def create_user(self, email, password=None, **extra_fields):           .....       def create_superuser(self, email, password, **extra_fields):           ..... 

This solution does result in repetition of some of Django's built-in code (mainly model fields that already exist in AbstractUser such as 'first_name', 'last_name' etc.) but also in a cleaner User object and database table.

It is a real shame that the flexibily introduced in 1.5 with USERNAME_FIELD can not be used to actualy create a flexible User model under all existing constrains.

EDIT: There is a comprehensive worked example available in the official docs: https://docs.djangoproject.com/en/dev/topics/auth/customizing/#a-full-example

Answer 2

If your real target is unique "email" values, and ignoring "username" values, then you may:

• Fill "username" with e.g. sha256(user.email).hexdigest()[:30]

• Add uniqueness this way:

  class User(AbstractUser):     class Meta:         unique_together = ('email', ) 

This results in:

CREATE TABLE "myapp_user" (     ...     "email" varchar(75) NOT NULL,     UNIQUE ("email") ) 

works just as expected, and is pretty simple.