Django Custom User - Not using username - Username unique constraint failed

So I created my own user model by sub-classing AbstractBaseUser as is recommended by the docs. The goal here was to use a new field called mob_phone as the identifying field for registration and log-in.

It works a charm - for the first user. It sets the username field as nothing - blank.But when I register a second user I get a "UNIQUE constraint failed: user_account_customuser.username".

I basically want to do away with the username field altogether. How can I achieve this?

I've tried lots of suggestions I found elsewhere but to no avail. I basically need to either find a way of making the username field not unique or remove it altogether.

Cheers!

Dean

models.py

from django.contrib.auth.models import AbstractUser, BaseUserManager


class MyUserManager(BaseUserManager):
    def create_user(self, mob_phone, email, password=None):
        """
        Creates and saves a User with the given mobile number and password.
        """
        if not mob_phone:
            raise ValueError('Users must mobile phone number')

        user = self.model(
            mob_phone=mob_phone,
            email=email
        )

        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_superuser(self, mob_phone, email, password):
        """
        Creates and saves a superuser with the given email, date of
        birth and password.
        """
        user = self.create_user(
            mob_phone=mob_phone,
            email=email,
            password=password
        )
        user.is_admin = True
        user.save(using=self._db)
        return user


class CustomUser(AbstractUser):
    mob_phone = models.CharField(blank=False, max_length=10, unique=True)
    is_admin = models.BooleanField(default=False)
    objects = MyUserManager()

    # override username field as indentifier field
    USERNAME_FIELD = 'mob_phone'
    EMAIL_FIELD = 'email'

    def get_full_name(self):
        return self.mob_phone

    def get_short_name(self):
        return self.mob_phone

    def __str__(self):              # __unicode__ on Python 2
        return self.mob_phone

    def has_perm(self, perm, obj=None):
        "Does the user have a specific permission?"
        # Simplest possible answer: Yes, always
        return True

    def has_module_perms(self, app_label):
        "Does the user have permissions to view the app `app_label`?"
        # Simplest possible answer: Yes, always
        return True

    @property
    def is_staff(self):
        "Is the user a member of staff?"
        # Simplest possible answer: All admins are staff
        return self.is_admin

Stacktrace:

Traceback (most recent call last): File "manage.py", line 22, in execute_from_command_line(sys.argv) File "/home/dean/.local/lib/python3.5/site-packages/django/core/management/init.py", line 363, in execute_from_command_line utility.execute() File "/home/dean/.local/lib/python3.5/site-packages/django/core/management/init.py", line 355, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "/home/dean/.local/lib/python3.5/site-packages/django/core/management/base.py", line 283, in run_from_argv self.execute(*args, **cmd_options) File "/home/dean/.local/lib/python3.5/site-packages/django/contrib/auth/management/commands/createsuperuser.py", line 63, in execute return super(Command, self).execute(*args, **options) File "/home/dean/.local/lib/python3.5/site-packages/django/core/management/base.py", line 330, in execute output = self.handle(*args, **options) File "/home/dean/.local/lib/python3.5/site-packages/django/contrib/auth/management/commands/createsuperuser.py", line 183, in handle self.UserModel._default_manager.db_manager(database).create_superuser(**user_data) File "/home/dean/Development/UrbanFox/UrbanFox/user_account/models.py", line 43, in create_superuser password=password File "/home/dean/Development/UrbanFox/UrbanFox/user_account/models.py", line 32, in create_user user.save(using=self._db) File "/home/dean/.local/lib/python3.5/site-packages/django/contrib/auth/base_user.py", line 80, in save super(AbstractBaseUser, self).save(*args, **kwargs) File "/home/dean/.local/lib/python3.5/site-packages/django/db/models/base.py", line 807, in save force_update=force_update, update_fields=update_fields) File "/home/dean/.local/lib/python3.5/site-packages/django/db/models/base.py", line 837, in save_base updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields) File "/home/dean/.local/lib/python3.5/site-packages/django/db/models/base.py", line 923, in _save_table result = self._do_insert(cls._base_manager, using, fields, update_pk, raw) File "/home/dean/.local/lib/python3.5/site-packages/django/db/models/base.py", line 962, in _do_insert using=using, raw=raw) File "/home/dean/.local/lib/python3.5/site-packages/django/db/models/manager.py", line 85, in manager_method return getattr(self.get_queryset(), name)(*args, **kwargs) File "/home/dean/.local/lib/python3.5/site-packages/django/db/models/query.py", line 1076, in _insert return query.get_compiler(using=using).execute_sql(return_id) File "/home/dean/.local/lib/python3.5/site-packages/django/db/models/sql/compiler.py", line 1107, in execute_sql cursor.execute(sql, params) File "/home/dean/.local/lib/python3.5/site-packages/django/db/backends/utils.py", line 80, in execute return super(CursorDebugWrapper, self).execute(sql, params) File "/home/dean/.local/lib/python3.5/site-packages/django/db/backends/utils.py", line 65, in execute return self.cursor.execute(sql, params) File "/home/dean/.local/lib/python3.5/site-packages/django/db/utils.py", line 94, in exit six.reraise(dj_exc_type, dj_exc_value, traceback) File "/home/dean/.local/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise raise value.with_traceback(tb) File "/home/dean/.local/lib/python3.5/site-packages/django/db/backends/utils.py", line 65, in execute return self.cursor.execute(sql, params) File "/home/dean/.local/lib/python3.5/site-packages/django/db/backends/sqlite3/base.py", line 328, in execute return Database.Cursor.execute(self, query, params) django.db.utils.IntegrityError: UNIQUE constraint failed: user_account_customuser.username