Tag Archives: #Python pit filling guide

[Solved] AttributeError: ‘Manager‘ object has no attribute ‘get_by_natural_key‘

Problem description

E:\SweetYaya\MyProj03>python manage.py createsuperuser
Identifier: 12
Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\__init__.py", line 419, in execute_from_command_line
    utility.execute()
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\__init__.py", line 413, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\base.py", line 354, in run_from_argv
    self.execute(*args, **cmd_options)
  File "D:\Program Files\Python36\lib\site-packages\django\contrib\auth\management\commands\createsuperuser.py", line 79, in execute
    return super().execute(*args, **options)
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\base.py", line 398, in execute
    output = self.handle(*args, **options)
  File "D:\Program Files\Python36\lib\site-packages\django\contrib\auth\management\commands\createsuperuser.py", line 113, in handle
    error_msg = self._validate_username(username, verbose_field_name, database)
  File "D:\Program Files\Python36\lib\site-packages\django\contrib\auth\management\commands\createsuperuser.py", line 234, in _validate_username
    self.UserModel._default_manager.db_manager(database).get_by_natural_key(username)
AttributeError: 'Manager' object has no attribute 'get_by_natural_key'

terms of settlement

Add to the defined model

class SysUsers(models.Model):
    
	...
	# add
    objects = UserManager()
	
	...

django.db.utils.OperationalError: no such table: django_admin_log

Problem orientation

Using Python shell to delete custom user table data

from MyApp import models
dU = models.SysUsers.objects.all()
dU.delete()

The error is as follows

django.db.utils.OperationalError: no such table: django_admin_log

terms of settlement

Direct migrate may not work. Parameters should be added as follows

python manage.py makemigrations
python manage.py migrate --run-syncdb

ValueError: The field admin.LogEntry.user was declared with a lazy reference to ‘MyApp.sysusers‘

Problem description

E:\SweetYaya\MyProj03>python manage.py migrate
Operations to perform:
  Apply all migrations: MyApp, admin, auth, contenttypes, sessions
Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\__init__.py", line 419, in execute_from_command_line
    utility.execute()
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\__init__.py", line 413, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\base.py", line 354, in run_from_argv
    self.execute(*args, **cmd_options)
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\base.py", line 398, in execute
    output = self.handle(*args, **options)
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\base.py", line 89, in wrapped
    res = handle_func(*args, **kwargs)
  File "D:\Program Files\Python36\lib\site-packages\django\core\management\commands\migrate.py", line 202, in handle
    pre_migrate_apps = pre_migrate_state.apps
  File "D:\Program Files\Python36\lib\site-packages\django\utils\functional.py", line 48, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "D:\Program Files\Python36\lib\site-packages\django\db\migrations\state.py", line 208, in apps
    return StateApps(self.real_apps, self.models)
  File "D:\Program Files\Python36\lib\site-packages\django\db\migrations\state.py", line 277, in __init__
    raise ValueError("\n".join(error.msg for error in errors))
ValueError: The field admin.LogEntry.user was declared with a lazy reference to 'MyApp.sysuser', but app 'MyApp' doesn't provide model 'sysuser'.

Find your own python3. X and enter the site packages/Django/contrib/admin/migrations file directory__ init__. Py file, delete all others（ Be careful not to__ init__. If you delete the PY file, don’t delete the migrations in the folder contrib/contenttypes. Otherwise, the function of migrate will be invalid and Django can only be removed.