AttributeError: 'Manager' object has no attribute 'get_by_natural_key' error in Django?

Question

I am using Django '1.5c1'. I have this line in my settings.py:

AUTH_USER_MODEL = 'fileupload.galaxyuser'

Here's my Galaxyuser model:

class GalaxyUser(models.Model):
    id = models.IntegerField(primary_key=True)
    create_time = models.DateTimeField(null=True, blank=True)
    update_time = models.DateTimeField(null=True, blank=True)
    email = models.CharField(max_length=765)
    password = models.CharField(max_length=120)
    external = models.IntegerField(null=True, blank=True)
    deleted = models.IntegerField(null=True, blank=True)
    purged = models.IntegerField(null=True, blank=True)
    username = models.CharField(max_length=765, blank=True)
    form_values_id = models.IntegerField(null=True, blank=True)
    disk_usage = models.DecimalField(null=True, max_digits=16, decimal_places=0, blank=True)
    class Meta:
        db_table = u'galaxy_user'

I want to authenticate from Galaxyuser model. However when I login I am getting this error:

AttributeError: 'Manager' object has no attribute 'get_by_natural_key'

What am I doing wrong?

Edit: Traceback:

Traceback:
File "/usr/local/lib/python2.6/dist-packages/django/core/handlers/base.py" in get_response
  115.                         response = callback(request, *callback_args, **callback_kwargs)
File "/home/zurelsoft/workspace/genalytics/fileupload/backend.py" in login_backend
  26.         user = authenticate(username=username, password=password)
File "/usr/local/lib/python2.6/dist-packages/django/contrib/auth/__init__.py" in authenticate
  59.             user = backend.authenticate(**credentials)
File "/usr/local/lib/python2.6/dist-packages/django/contrib/auth/backends.py" in authenticate
  16.             user = UserModel.objects.get_by_natural_key(username)

Exception Type: AttributeError at /login_backend/
Exception Value: 'Manager' object has no attribute 'get_by_natural_key'

Selfabuse

can you provide your settings.py file – Pravit

paste the track back also – Pravit

django will create id for you no need to add id in your model and if you are using the django user model then username must be OneToOne field for the User model check the docs – Pravit

The only thing I want to do is authenticate from the GalaxyUser model using the build in Django authentication function. I am getting error while doing do. Thanks – Selfabuse

Answer 1

You have created a new user model but you have not yet specified a manager for that model. If you're not yet familiar with managers in Django I suggest reading the documentation on that first. As the Django 1.5 say (source):

You should also define a custom manager for your User model. If your User model defines username and email fields the same as Django's default User, you can just install Django's UserManager; however, if your User model defines different fields, you will need to define a custom manager that extends BaseUserManager providing two additional methods: create_user() and create_superuser().

In short, if your model uses the same username and email fields as Django's User model then you can write:

from django.contrib.auth.models import UserManager

class GalaxyUser(models.Model):
    id = models.IntegerField(primary_key=True)
    create_time = models.DateTimeField(null=True, blank=True)
    update_time = models.DateTimeField(null=True, blank=True)
    email = models.CharField(max_length=765)
    password = models.CharField(max_length=120)
    external = models.IntegerField(null=True, blank=True)
    deleted = models.IntegerField(null=True, blank=True)
    purged = models.IntegerField(null=True, blank=True)
    username = models.CharField(max_length=765, blank=True)
    form_values_id = models.IntegerField(null=True, blank=True)
    disk_usage = models.DecimalField(null=True, max_digits=16, decimal_places=0, blank=True)

    objects = UserManager()

    class Meta:
        db_table = u'galaxy_user'

Alternatively, you'll need to subclass BaseUserManager (also in django.contrib.auth.models) and implement the desired methods. Then, you'll need to assign it to the objects variable for your model.

Pibgorn

I am getting this error after implementing this: type object 'User' has no attribute 'USERNAME_FIELD' – Selfabuse

I have renamed my model to User from GalaxyUser. – Selfabuse

I read the documentation you provided but I couldn't find the solution. Can you help me on this? – Selfabuse

I have solved this using: USERNAME_FIELD = 'username' but I get another error: 'User' object has no attribute 'check_password' – Selfabuse

I think you can solve that by extending your user model from AbstractBaseUser: docs.djangoproject.com/en/1.5/topics/auth/customizing/… – Pibgorn

Did like this: class User(AbstractBaseUser) but got another error: FieldError: Local field 'password' in class 'User' clashes with field of similar name from base class 'AbstractBaseUser' – Selfabuse

Since I want to authenticate from another table I don't want to subclass AbstractBaseUser. – Selfabuse

some pretty unhelpful comments here - if we've landed here, then we're not understanding the docs. – Persona

The link to the managers docs is outdated; here is the (2020) new version: https://docs.djangoproject.com/en/3.0/topics/db/managers/ – Flitting

Answer 2

for me.. I had forgotten to add Parentheses end of manager..

objects = UserManager

objects = UserManager()

Clarisclarisa

My problem was I didn't even have "objects = Usermanager()" or any variation of it. Adding this close to the bottom of the class and making sure to use "from django.contrib.auth.models import UserManager" solved it for me. This answer helped me notice it. – Whereupon

Answer 3

If you have a UserManger class for your GalaxyUser class, make sure you add objects = UserManager() to that

Disentomb

Answer 4

You have to create a user manager for the custom model. Maybe GalaxyUserManager. Then add objects = GalaxyUserManager() to your user model

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