Django custom user field clashes with AbstractBaseUser

Question

I am building a Django project from an existing database. The database is being used by other systems, so I cannot change its schema. This is my current custom User model:

Answer 1

I can't figure out a good way to do this, so I'll give you two rather unsatisfying (but workable) solutions hacks:

1. Rather than inheriting from AbstractBaseUser, take advantage of Django's open-source-ness and copy their AbstractBaseUser code (it's located at <...>lib/python3.4/site-packages/django/contrib/auth/models.py) and use a direct implementation of it with column_name='last_login_date' in the last_login field. (the AbstractBaseUser class is also here (version 1.7))

2. Edit <...>lib/python3.4/site-packages/django/contrib/auth/models.py directly (resulting in non-portable code that will not work on another django installation without hacking it too)