python - 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'

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 — masterofdestiny
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 — pynovice

Simeon Visser Simeon Visser · Accepted Answer · 2013-02-06T08:44:10

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.

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

1 Answers