I do not use the username field of the auth_user.

Using Django Getting Started
1

Hello everyone. In my application the login is done by email and not by a username. Is it advisable to create a custom model of the User model or is it possible to just copy the email field to the username?

Because currently the username field is empty and I get the following console output:

 django.db.utils.IntegrityError: UNIQUE constraint failed: auth_user.username

Which I understand that I get it because when the first user registers, the username field is left blank.

Is it advisable to copy what goes in the email field in the username field?

2

Sure - that’s one way to do it.

There’s no “right” or “wrong” here - it’s an architectural decision that should be made in the context of the overall requirements for the system.

3

If you’re not willing to use the username field, you can remove it.

from django.contrib.auth.models import AbstractBaseUser
from django.contrib.auth.models import PermissionsMixin


class YourUserModel(PermissionsMixin, AbstractBaseUser):
  username = None
  # Your other fields
4

That is another way to do it, but then he’s no longer using the standard default User model.