Can django's auth_user.username be varchar(75)

Question

Is there anything wrong with running alter table on auth_user to make username be varchar(75) so it can fit an email? What does that break if anything?

If you were to change auth_user.username to be varchar(75) where would you need to modify django? Is it simply a matter of changing 30 to 75 in the source code?

username = models.CharField(_('username'), max_length=30, unique=True, help_text=_("Required. 30 characters or fewer. Letters, numbers and @/./+/-/_ characters"))

Or is there other validation on this field that would have to be changed or any other repercussions to doing so?

See comment discussion with bartek below regarding the reason for doing it.

Edit: Looking back on this after many months. For anyone who doesn't know the premise: Some apps don't have a requirement or desire to use a username, they use only email for registration & auth. Unfortunately in django auth.contrib, username is required. You could start putting emails in the username field, but the field is only 30 char and emails may be long in the real world. Potentially even longer than the 75 char suggested here, but 75 char accommodates most sane email addresses. The question is aimed at this situation, as encountered by email-auth-based applications.

Answer 1

If you are using venv (virtual environment), the simplest solution probably is just update the core code directly, i.e. opening the following two files: - - venv/lib/python2.7/sites-packages/django/contrib/auth/model.py - venv/lib/python2.7/sites-packages/django/contrib/auth/forms.py Search for all username field and change max_length from 30 to 100. It is safe since you are already using venv so it won't affect any other Django project.

Answer 2

Updated solution for the Django 1.3 version (without modifying manage.py):

Create new django-app:

monkey_patch/
    __init__.py
    models.py

Install it as first: (settings.py)

INSTALLED_APPS = (
    'monkey_patch', 
    #...
)

Here is models.py:

from django.contrib.auth.models import User
from django.core.validators import MaxLengthValidator

NEW_USERNAME_LENGTH = 300

def monkey_patch_username():
    username = User._meta.get_field("username")
    username.max_length = NEW_USERNAME_LENGTH
    for v in username.validators:
        if isinstance(v, MaxLengthValidator):
            v.limit_value = NEW_USERNAME_LENGTH

monkey_patch_username()

Answer 3

As far as I know one can override user model since Django 1.5 which will solve a problem. Simple example here

Answer 4

The best solution is to use email field for email and the username for username.

In the input login form validation, find whether the data is username or the email and if email, query the email field.

This only requires monkey patching the contrib.auth.forms.login_form which is a few lines in the corresponding view.

And it is far better than trying to modify the models and the database tables.

Answer 5

I am using django 1.4.3 which makes it pretty easy and I did not have to change anything else in my code after realising I wanted to use long email addresses as usernames.

If you have direct access to the database, change it there to the amount of characters you would like to, in my case 100 characters.

In your app model (myapp/models.py) add the following

from django.contrib.auth.models import User

class UserProfile(models.Model):

    # This field is required.
    User._meta.get_field("username").max_length = 100
    user = models.OneToOneField(User)

Then in your settings.py you specify the model:

AUTH_USER_MODEL = 'myapp.UserProfile'

Answer 6

Based on Clément and Matt Miller's great combined answer above, I've pulled together a quick app that implements it. Pip install, migrate, and go. Would put this as a comment, but don't have the cred yet!

https://github.com/GoodCloud/django-longer-username

EDIT 2014-12-08

The above module is now deprecated in favor of https://github.com/madssj/django-longer-username-and-email