Develop Reference

python manage.py test: django.db.utils.OperationalError: no such table: accounts_user

I'm fairly new at testing and while trying to run test for my django project using python manage.py test i end up getting django.db.utils.OperationalError: no such table: accounts_user.
I have the User model within the accounts app and the accounts app has been added to installed app within my settings.py
I've run makemgirations and migrate for all project apps, i've also gone into the project shell and try creating a user from User model in the accounts app and all of these works well, but when i run my test i get an error.
below is the test i'm trying to run which generates the error
from django.test import TestCase
from django.contrib.auth import get_user_model
class UserTestCase(TestCase):
def setUp(self):
USER = get_user_model()
USER.objects.create(
email="johndoe#example.com", first_name="John", last_name="Doe"
)
USER.objects.create(
email="janedoe#example.com", first_name="Jane", last_name="Doe"
)
def test_user_full_name(self):
""" A user's fullname correctly identified """
jane = USER.objects.get(email="janedoe#example.com")
john = USER.objects.get(email="johndoe#example.com")
self.assertEqual(jane.get_full_name(), "Jane Doe")
self.assertEqual(john.get_full_name(), "John Doe")
and below is the code i ran within project shell that works
from django.contrib.auth import get_user_model
USER = get_user_model()
USER.objects.create(
email="johndoe#example.com", first_name="John", last_name="Doe"
)
USER.objects.create(
email="janedoe#example.com", first_name="Jane", last_name="Doe"
)
USER.objects.all()
# returns both object that has been added
and below is my database settings
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
'TEST': {
'test_NAME': 'test_db',
}
}
}
Please how can this be resolved
Below is the full stack trace
$ python manage.py test
Creating test database for alias 'default'...
Traceback (most recent call last):
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\utils.py", line 82, in _execute
return self.cursor.execute(sql)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\sqlite3\base.py", line 381, in execute
return Database.Cursor.execute(self, query)
sqlite3.OperationalError: no such table: accounts_user
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\__init__.py", line 381, in execute_from_command_line
utility.execute()
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\commands\test.py", line 23, in run_from_argv
super().run_from_argv(argv)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\base.py", line 323, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\base.py", line 364, in execute
output = self.handle(*args, **options)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\commands\test.py", line 53, in handle
failures = test_runner.run_tests(test_labels)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\test\runner.py", line
629, in run_tests
old_config = self.setup_databases(aliases=databases)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\test\runner.py", line
554, in setup_databases
self.parallel, **kwargs
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\test\utils.py", line 174, in setup_databases
serialize=connection.settings_dict.get('TEST', {}).get('SERIALIZE', True),
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\base\creation.py", line 72, in create_test_db
run_syncdb=True,
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\__init__.py", line 148, in call_command
return command.execute(*args, **defaults)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\base.py", line 364, in execute
output = self.handle(*args, **options)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\commands\migrate.py", line 203, in handle
self.sync_apps(connection, executor.loader.unmigrated_apps)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\core\management\commands\migrate.py", line 341, in sync_apps
self.stdout.write(" Running deferred SQL...\n")
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\sqlite3\schema.py", line 34, in __exit__
self.connection.check_constraints()
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\sqlite3\base.py", line 341, in check_constraints
column_name, referenced_column_name,
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\utils.py", line 67, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\utils.py", line 76, in _execute_with_wrappers
return executor(sql, params, many, context)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\utils.py", line 82, in _execute
return self.cursor.execute(sql)
File "C:\Users\i-am-prinx\.virtualenvs\ProjectName-2t3W9LfY\lib\site-packages\django\db\backends\sqlite3\base.py", line 381, in execute
return Database.Cursor.execute(self, query)
django.db.utils.OperationalError: no such table: accounts_user
Tools and versions
django v 2.2
python v 3.6

The main cause of this issue was because an app within the project had a model with a foreignkey field to the User model and this said app was not having migrations folder and the models in the app (including those having foreignkey reference to the User model ) was not migrated (note that this said app is in installed app).
I resolved this issue by following these steps
** steps and explanation of what i noticed**
I deleted the db.sqlite3 file on my project root
I deleted the migrations directory on all apps ( not all apps had migrations folder though i ran python manage.py makemigrations, reason for this i really don't know ). The only app that was having migrations folder was the accounts app.
I then explicitly ran makemigrations for all apps ( test worked even without explicitly running migrate command, so far makemigrations has been run) and then i ran python manage.py migrate command
** for the above code **
class UserTestCase(TestCase):
def setUp(self):
USER = get_user_model() # <--- doing this here generates error when using USER.get() in the test_... methods
USER.objects.create(
email="johndoe#example.com", first_name="John", last_name="Doe"
)
USER.objects.create(
email="janedoe#example.com", first_name="Jane", last_name="Doe"
)
def test_user_full_name(self):
""" A user's fullname correctly identified """
jane = USER.objects.get(email="janedoe#example.com")
john = USER.objects.get(email="johndoe#example.com")
self.assertEqual(jane.get_full_name(), "Jane Doe")
self.assertEqual(john.get_full_name(), "John Doe")
The above code will fail and the correct code should be
USER = get_user_model()
class UserTestCase(TestCase):
def setUp(self):
USER.objects.create(
email="johndoe#example.com", first_name="John", last_name="Doe"
)
USER.objects.create(
email="janedoe#example.com", first_name="Jane", last_name="Doe"
)
def test_user_full_name(self):
""" A user's fullname correctly identified """
jane = USER.objects.get(email="janedoe#example.com")
john = USER.objects.get(email="johndoe#example.com")
self.assertEqual(jane.get_full_name(), "Jane Doe")
self.assertEqual(john.get_full_name(), "John Doe")
I hope this is able to help someone

This worked for me;
Delete all the migration files and then run
python .\manage.py migrate --run-syncdb
It should work.

Try setting your database settings like so (this depends on which django version you are using):
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
}
}

Django: dynamic model fields and migrations

I have problems understanding how django's model fields work. What I want to achieve is something like a PriceField (DecimalField), that dynamically creates/injects another model field, let's say a currency (CharField) field.
I have read an interesing blog posts about this topic at https://blog.elsdoerfer.name/2008/01/08/fuzzydates-or-one-django-model-field-multiple-database-columns/. I think (and hope) that I've understood the core messages of the articles. But as most of them are a little bit outdated, I don't know if they are still valid for current django versions and my below code.
I use Django 1.11.4, Python 3.6.2, and a clean app created with ./manage.py startapp testing. The code in models.py:
from django.db import models
from django.db.models import signals
_currency_field_name = lambda name: '{}_extension'.format(name)
class PriceField(models.DecimalField):
def contribute_to_class(self, cls, name):
# add the extra currency field (CharField) to the class
if not cls._meta.abstract:
currency_field = models.CharField(
max_length=3,
editable=False,
null=True,
blank=True
)
cls.add_to_class(_currency_field_name(name), currency_field)
# add the original price field (DecimalField) to the class
super().contribute_to_class(cls, name)
# TODO: set the descriptor
# setattr(cls, self.name, FooDescriptor(self))
class FooModel(models.Model):
price = PriceField('agrhhhhh', decimal_places=3, max_digits=10, blank=True, null=True)
The problems come if I try to create migrations for that models. If executing python manage.py makemigrations following message is shown:
Migrations for 'testing':
testing/migrations/0001_initial.py
- Create model FooModel
Migration file 0001_initial.py has the following content:
# Generated by Django 1.11.4 on 2017-09-11 18:02
from __future__ import unicode_literals
from django.db import migrations, models
import testing.models
class Migration(migrations.Migration):
initial = True
dependencies = [
]
operations = [
migrations.CreateModel(
name='FooModel',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('price', testing.models.PriceField(blank=True, decimal_places=3, max_digits=10, null=True, verbose_name='agrhhhhh')),
('price_extension', models.CharField(blank=True, editable=False, max_length=3, null=True)),
],
),
]
For me this looks OK so far. But if I then execute ./manage.py migrate testing, django shouts:
Operations to perform:
Apply all migrations: testing
Running migrations:
Applying testing.0001_initial...Traceback (most recent call last):
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/utils.py", line 63, in execute
return self.cursor.execute(sql)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py", line 326, in execute
return Database.Cursor.execute(self, query)
sqlite3.OperationalError: duplicate column name: price_extension
Why does it error out on a duplicate column name: price_extension, when there is only one such field defined in the migrations file? Where does this duplicate field come from and is there a fix for this situation? Thanks!
Edit 1
This exception not only happens with an already existing database but also when I start with an empty database from scratch (deleting SQLite file). After the migrate command failed this is the structure of the DB:
./manage.py dbshell
sqlite> .tables
django_migrations
sqlite> .schema
CREATE TABLE "django_migrations" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "app" varchar(255) NOT NULL, "name" varchar(255) NOT NULL, "applied" datetime NOT NULL);
sqlite> select * from django_migrations;
sqlite>
And full stacktrace:
./manage.py migrate testing
Operations to perform:
Apply all migrations: testing
Running migrations:
Applying testing.0001_initial...Traceback (most recent call last):
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/utils.py", line 63, in execute
return self.cursor.execute(sql)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py", line 326, in execute
return Database.Cursor.execute(self, query)
sqlite3.OperationalError: duplicate column name: price_extension
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "./manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/core/management/__init__.py", line 363, in execute_from_command_line
utility.execute()
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/core/management/__init__.py", line 355, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/core/management/base.py", line 283, in run_from_argv
self.execute(*args, **cmd_options)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/core/management/base.py", line 330, in execute
output = self.handle(*args, **options)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 204, in handle
fake_initial=fake_initial,
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/migrations/executor.py", line 115, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/migrations/executor.py", line 145, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/migrations/executor.py", line 244, in apply_migration
state = migration.apply(state, schema_editor)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/migrations/migration.py", line 129, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/migrations/operations/models.py", line 97, in database_forwards
schema_editor.create_model(model)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 303, in create_model
self.execute(sql, params or None)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 120, in execute
cursor.execute(sql, params)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/utils.py", line 80, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/cachalot/monkey_patch.py", line 113, in inner
out = original(cursor, sql, *args, **kwargs)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/utils.py", line 65, in execute
return self.cursor.execute(sql, params)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/utils.py", line 63, in execute
return self.cursor.execute(sql)
File "/usr/local/var/pyenv/versions/stockmanagement-3.6.2/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py", line 326, in execute
return Database.Cursor.execute(self, query)
django.db.utils.OperationalError: duplicate column name: price_extension
Edit 2
A git repository with the above code can be found under: https://github.com/hetsch/django_testing. This error happens also if one clones this repository (clean project without any DB), calls makemigrations and then migrate.

According to Django ticket #22555 https://code.djangoproject.com/ticket/22555, this method of adding fields is not officially supported. Nonetheless, I made it work with the following simple fix:
def contribute_to_class(self, cls, name):
# add the extra currency field (CharField) to the class
# and prevent adding another field instance if the
# field was allready attached.
if not cls._meta.abstract and not hasattr(cls, _currency_field_name(name)):
currency_field = models.CharField(
max_length=3,
editable=False,
null=True,
blank=True
)
cls.add_to_class(_currency_field_name(name), currency_field)

Django: model OneToOneField with User can't add default value

I have an model and I want to add an OneToOneField to hold the creator of an object:
models.py
creator = models.OneToOneField(User, blank=True,
default=User.objects.filter(
username="antoni4040"))
I already have a database with items and just want the default value to be the admin user, which has the username "antoni4040". When I try to migrate without the default field it asks for a default value, so I can't get away with it. But here's what I get when running makemigrations:
Migrations for 'jokes_app':
0008_joke_creator.py:
- Add field creator to joke
Traceback (most recent call last):
File "./manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
utility.execute()
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/core/management/__init__.py", line 345, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/core/management/base.py", line 348, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/core/management/base.py", line 399, in execute
output = self.handle(*args, **options)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/core/management/commands/makemigrations.py", line 150, in handle
self.write_migration_files(changes)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/core/management/commands/makemigrations.py", line 178, in write_migration_files
migration_string = writer.as_string()
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/db/migrations/writer.py", line 167, in as_string
operation_string, operation_imports = OperationWriter(operation).serialize()
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/db/migrations/writer.py", line 124, in serialize
_write(arg_name, arg_value)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/db/migrations/writer.py", line 88, in _write
arg_string, arg_imports = MigrationWriter.serialize(_arg_value)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/db/migrations/writer.py", line 433, in serialize
return cls.serialize_deconstructed(path, args, kwargs)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/db/migrations/writer.py", line 318, in serialize_deconstructed
arg_string, arg_imports = cls.serialize(arg)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/db/migrations/writer.py", line 517, in serialize
item_string, item_imports = cls.serialize(item)
File "/home/antoni4040/Documents/Jokes_Website/django-jokes/venv/lib/python3.4/site-packages/django/db/migrations/writer.py", line 540, in serialize
"topics/migrations/#migration-serializing" % (value, get_docs_version())
ValueError: Cannot serialize: <User: antoni4040>
There are some values Django cannot serialize into migration files.
For more, see https://docs.djangoproject.com/en/1.9/topics/migrations/#migration-serializing
What am I doing wrong?

You are using the queryset User.objects.filter(username="antoni4040"). To get a model instance, you would use User.objects.get(username="antoni4040").
However, you shouldn't use a a model instance for as the default in the model field. There's no error handling if the user does not exist in the database. In fact, if models.py is loaded before you run the initial migrations, then the User table won't even exist so the query will give an error.
The logic to set the default user should go in the view (or Django admin) instead of the models file.
In the admin, you could define a custom form that sets the initial value for the creator field.
class MyModelForm(forms.ModelForm):
class Meta:
model = MyModel
def __init__(self, *args, **kwargs):
try:
user = User.objects.get(username="antoni4040")
kwargs['initial']['creator'] = user
except MyModel.DoesNotExist:
pass
super(MyModelForm, self).__init__(*args, **kwargs)
Then use that model form in your admin.
class MyModelAdmin(admin.ModelAdmin):
form = MyModelForm
...

If you really wanted to do this you can open up a shell and get the id for that User, then set the default to that.
The problem is, why would you do that? The first time you add a model it will use the default correctly. The second time you try to do that, it will fail because it's one to one, not many to one, so it will fail.

django.db.utils.IntegrityError: (1062, "Duplicate entry '' for key 'slug'")

I'm trying to follow the tangowithdjango book and must add a slug to update the category table. However I'm getting an error after trying to migrate the databases.
http://www.tangowithdjango.com/book17/chapters/models_templates.html#creating-a-details-page
I didn't provide a default value for the slug, so Django asked me to provide one and as the book instructed I type in ''.
It's worth noticing that instead of using sqlite as in the original book I'm using mysql.
models.py
from django.db import models
from django.template.defaultfilters import slugify
# Create your models here.
class Category(models.Model):
name = models.CharField(max_length=128, unique=True)
views = models.IntegerField(default=0)
likes = models.IntegerField(default=0)
slug = models.SlugField(unique=True)
def save(self, *args, **kwargs):
self.slug = slugify(self.name)
super(Category, self).save(*args, **kwargs)
class Meta:
verbose_name_plural = "Categories"
def __unicode__(self):
return self.name
class Page(models.Model):
category = models.ForeignKey(Category)
title = models.CharField(max_length=128)
url = models.URLField()
views = models.IntegerField(default=0)
def __unicode__(self):
return self.title
The command prompt
sudo python manage.py migrate
Operations to perform:
Apply all migrations: admin, rango, contenttypes, auth, sessions
Running migrations:
Applying rango.0003_category_slug...Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
utility.execute()
File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 377, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 288, in run_from_argv
self.execute(*args, **options.__dict__)
File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 338, in execute
output = self.handle(*args, **options)
File "/usr/local/lib/python2.7/dist-packages/django/core/management/commands/migrate.py", line 160, in handle
executor.migrate(targets, plan, fake=options.get("fake", False))
File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 63, in migrate
self.apply_migration(migration, fake=fake)
File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 97, in apply_migration
migration.apply(project_state, schema_editor)
File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/migration.py", line 107, in apply
operation.database_forwards(self.app_label, schema_editor, project_state, new_state)
File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/operations/fields.py", line 37, in database_forwards
field,
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/mysql/schema.py", line 42, in add_field
super(DatabaseSchemaEditor, self).add_field(model, field)
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/schema.py", line 411, in add_field
self.execute(sql, params)
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/schema.py", line 98, in execute
cursor.execute(sql, params)
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 81, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 65, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python2.7/dist-packages/django/db/utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 65, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/mysql/base.py", line 128, in execute
return self.cursor.execute(query, args)
File "/usr/local/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 205, in execute
self.errorhandler(self, exc, value)
File "/usr/local/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
raise errorclass, errorvalue
django.db.utils.IntegrityError: (1062, "Duplicate entry '' for key 'slug'")

Let's analyse it step by step:
You're adding slug field with unique = True, that means: each record must have different value, there can't be two records with same value in slug
You're creating migration: django asks you for default value for fields that exists already in database, so you provided '' (empty string) as that value.
Now django is trying to migrate your database. In database we have at least 2 records
First record is migrated, slug column is populated with empty string. That's good because no other record is having empty string in slug field
Second record is migrated, slug column is populated with empty string. That fails, because first record already have empty string in slug field. Exception is raised and migration is aborted.
That's why your migration fails. All you should do is to edit migration, copy migrations.AlterField operation twice, in first operation remove unique=True. Between that operations you should put migrations.RunPython operation and provide 2 parameters into that: generate_slugs and migrations.RunPython.noop.
Now you must create inside your migration function BEFORE migration class, name that function generate_slugs. Function should take 2 arguments: apps and schema_editor. In your function put at first line:
Category = apps.get_model('your_app_name', 'Category')
and now use Category.objects.all() to loop all your records and provide unique slug for each of them.

If you have more than one category in your table, then you cannot have unique=True and default='', because then you will have more than one category with slug=''. If your tutorial says to do this, then it's bad advice, although it might work in SQLite.
The correct approach to add a unique field to a model is:
Delete your current migration that isn't working.
Add the slug field, with unique=False. Create a new migration and run it.
Set a unique slug for every category. It sounds like the rango populate script might do this. Alternatively, you could write a migration to set the slugs, or even set them manually in the Django admin.
Change the slug field to unique=True. Create a new migration and run it.
If that's too difficult, then you could delete all your categories from your database except one. Then your current migration will run without having problems with the unique constraint. You can add the categories again afterwards.

You must have rows in your table already with empty slugs, which is a violation of the mysql unique constraint you created. You can update them manually by running manage.py dbshell to get to the mysql client, then updating the offending rows, e.g.
update table rango_category set slug = name where slug = '';
(assuming the rows with blank slugs have names). Or you can delete the rows with
delete from rango_category where slug = '';
After that, you should be able to run your migrations.

Python Django - getting error while creating model - extending user model with AbstractUser

I am trying to extend the user model using AbstractUser component. But I haven't been successful on this. After reseraching lot I wrote my model Employee(Extended user model) but now I get the below error when I do syncdb.
If anyone can help me by suggesting or running my models.py that would be great. when I run syncdb it asks superuser creation after i give the credentials I get a below error.
Error : (Complete traceback is pasted after the models.py)
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: epi_employee.emp_id may not be NULL
My models.py
from django.db import models
from django.contrib.auth.models import AbstractUser
from django.conf import settings
# Create your models here.
class Employee(AbstractUser):
emp_id = models.IntegerField('Employee Id', max_length=5,unique=True)
dob = models.DateField('Date of Birth', null=True,blank=True)
def __unicode__(self):
return self.get_full_name
class Department(models.Model):
name = models.CharField('Department Name',max_length=30, unique=True,default=0)
def __unicode__(self):
return self.name
class Report(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL)
dept = models.ForeignKey(Department, verbose_name="Department")
report1 = models.ForeignKey(Employee,null=True,blank=True, verbose_name=u'Primary Supervisor',related_name='Primary')
report2 = models.ForeignKey(Employee,null=True,blank=True, verbose_name=u'Secondary Supervisor',related_name='Secondary')
def __unicode__(self):
return self.user
def upload_to(instance, filename):
return 'images/%s/%s' % (instance.user.username, filename)
class thumbnail((models.Model)):
user = models.ForeignKey(settings.AUTH_USER_MODEL)
image = models.ImageField('Profile Pic',null=True, blank=True, upload_to=upload_to)
def __unicode__(self):
return self.user
class Passport(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL)
passport = models.CharField('Passport Number',max_length=15)
passportissue = models.CharField('Issuing City',max_length=15, default='Bangalore')
passportcountry = models.CharField('Issuing City',max_length=15, default='India')
passportstart = models.DateField('Valid From', null=True,blank=True)
passportend = models.DateField('Valid Till', null=True,blank=True)
def __unicode__(self):
return self.user
class CurrentAddress(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL)
address = models.TextField('Current Address')
city = models.CharField('City', max_length=20, default = 'Bangalore')
state = models.CharField('State', max_length=20, default= 'Karnataka')
country = models.CharField('Country', max_length=20, default = 'India')
mobile1 = models.IntegerField('Mobile1',max_length=12)
mobile2 = models.IntegerField('Mobile2', null=True, blank=True, max_length=12)
landline = models.IntegerField('Land Line',null=True, blank=True, max_length=12)
email = models.EmailField('Personal Email Id', blank=True)
def __unicode__(self):
return self.user
COMPLETE TRACE BACK: Please find the complete error which I am getting. Let me know if more information required
(testenv1) F:\djangoenv\testenv1\employee>python manage.py syncdb
Creating tables ...
Creating table django_admin_log
Creating table auth_permission
Creating table auth_group_permissions
Creating table auth_group
Creating table django_content_type
Creating table django_session
Creating table epi_employee_groups
Creating table epi_employee_user_permissions
Creating table epi_employee
Creating table epi_department
Creating table epi_report
Creating table epi_thumbnail
Creating table epi_passport
Creating table epi_currentaddress
You just installed Django's auth system, which means you don't have any superuse
rs defined.
Would you like to create one now? (yes/no): yes
Username: admin
Email address: admin#admin.com
Password:
Password (again):
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\__init__.
py", line 399, in execute_from_command_line
utility.execute()
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\__init__.
py", line 392, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\base.py",
line 242, in run_from_argv
self.execute(*args, **options.__dict__)
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\base.py",
line 285, in execute
output = self.handle(*args, **options)
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\base.py",
line 415, in handle
return self.handle_noargs(**options)
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\commands\
syncdb.py", line 112, in handle_noargs
emit_post_sync_signal(created_models, verbosity, interactive, db)
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\sql.py",
line 216, in emit_post_sync_signal
interactive=interactive, db=db)
File "F:\djangoenv\testenv1\lib\site-packages\django\dispatch\dispatcher.py",
line 185, in send
response = receiver(signal=self, sender=sender, **named)
File "F:\djangoenv\testenv1\lib\site-packages\django\contrib\auth\management\_
_init__.py", line 126, in create_superuser
call_command("createsuperuser", interactive=True, database=db)
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\__init__.
py", line 159, in call_command
return klass.execute(*args, **defaults)
File "F:\djangoenv\testenv1\lib\site-packages\django\core\management\base.py",
line 285, in execute
output = self.handle(*args, **options)
File "F:\djangoenv\testenv1\lib\site-packages\django\contrib\auth\management\c
ommands\createsuperuser.py", line 141, in handle
self.UserModel._default_manager.db_manager(database).create_superuser(**user
_data)
File "F:\djangoenv\testenv1\lib\site-packages\django\contrib\auth\models.py",
line 195, in create_superuser
**extra_fields)
File "F:\djangoenv\testenv1\lib\site-packages\django\contrib\auth\models.py",
line 186, in _create_user
user.save(using=self._db)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\models\base.py", line
545, in save
force_update=force_update, update_fields=update_fields)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\models\base.py", line
573, in save_base
updated = self._save_table(raw, cls, force_insert, force_update, using, upda
te_fields)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\models\base.py", line
654, in _save_table
result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\models\base.py", line
687, in _do_insert
using=using, raw=raw)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\models\manager.py", li
ne 232, in _insert
return insert_query(self.model, objs, fields, **kwargs)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\models\query.py", line
1511, in insert_query
return query.get_compiler(using=using).execute_sql(return_id)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\models\sql\compiler.py
", line 898, in execute_sql
cursor.execute(sql, params)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\backends\util.py", lin
e 69, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\backends\util.py", lin
e 53, in execute
return self.cursor.execute(sql, params)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\utils.py", line 99, in
__exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\backends\util.py", lin
e 53, in execute
return self.cursor.execute(sql, params)
File "F:\djangoenv\testenv1\lib\site-packages\django\db\backends\sqlite3\base.
py", line 450, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: epi_employee.emp_id may not be NULL

You defined emp_id as unique but not nullable, you can add null=True to the model,but seems to be that you wanna use emp_id as a primari_key, so to ensure that the field can not be null and must be unique you maybe wanna use a models.AutoField:
emp_id = models.AutoField(primary_key=True)
this guarantee that the field is unique an can not be null.
Now, for the max_length property and the model's name (Employee) I think that emp_id will be a number that the company gives you, for example my id in the company where I work is 0001544, so to avoid that problem you can create a custom manager:
from django.contrib.auth.models import BaseUserManager
class EmployeManager(BaseUserManager):
def create_user(self, username, email,emp_id, password=None):
if not username:
raise ValueError('Employers must have an username.')
if not email:
raise ValueError('Employers must have an email address.')
if not emp_id:
raise ValueError('Employers must have an employer id')
user = self.model(username=username, email=self.normalize_email(email), emp_id=emp_id)
user.set_password(password)
user.save(using=self._db)
return user
def create_superuser(self, username, email, emp_id, password):
user = self.create_user(username, email, emp_id, password)
user.is_admin = True
user.is_superuser = True
user.save(using=self._db)
return user
and then in the models file add this:
from myapp.managers import EmployeManager
and into your Employers Model ass this
objects = EmployeManager()
then you run python manage.py syncdb
hope this helps you, any doubt, tell me.

You defined emp_id unique but not nullable.
So when you created the superuser, django raises that emp_id can't be null.
If you want it as primary key remove that field.
If you want define it later put in emp_id field null=True
Anyway you can read here https://docs.djangoproject.com/en/dev/topics/db/models/#automatic-primary-key-fields
P.s. I see another error:
self.get_full_name()
But this is the super behaviour so you could delete it at all.