Django Unit Tests - Unable to create the django_migrations table

Question

I'm trying to write some unit tests and run them using manage.py test but the script can't create the django_migrations table for some reason.

Here is the full error:

Creating test database for alias 'default'...
Traceback (most recent call last):
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 83, in _execute
    return self.cursor.execute(sql)
psycopg2.ProgrammingError: no schema has been selected to create in
LINE 1: CREATE TABLE "django_migrations" ("id" serial NOT NULL PRIMA...
                     ^


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\migrations\recorder.py", line 55, in ensure_schema
    editor.create_model(self.Migration)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\base\schema.py", line 298, in create_model
    self.execute(sql, params or None)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\base\schema.py", line 117, in execute
    cursor.execute(sql, params)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 68, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 83, in _execute
    return self.cursor.execute(sql)
django.db.utils.ProgrammingError: no schema has been selected to create in
LINE 1: CREATE TABLE "django_migrations" ("id" serial NOT NULL PRIMA...
                     ^


During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\__init__.py", line 371, in execute_from_command_line
    utility.execute()
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\__init__.py", line 365, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\commands\test.py", line 26, in run_from_argv
    super().run_from_argv(argv)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\base.py", line 288, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\base.py", line 335, in execute
    output = self.handle(*args, **options)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\commands\test.py", line 59, in handle
    failures = test_runner.run_tests(test_labels)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\test\runner.py", line 601, in run_tests
    old_config = self.setup_databases()
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\test\runner.py", line 548, in setup_databases
    self.parallel, **kwargs
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\test\utils.py", line 176, in setup_databases
    serialize=connection.settings_dict.get('TEST', {}).get('SERIALIZE', True),
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\base\creation.py", line 68, in create_test_db
    run_syncdb=True,
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\__init__.py", line 141, in call_command
    return command.execute(*args, **defaults)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\base.py", line 335, in execute
    output = self.handle(*args, **options)
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\commands\migrate.py", line 200, in handle
    fake_initial=fake_initial,
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\migrations\executor.py", line 91, in migrate
    self.recorder.ensure_schema()
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\migrations\recorder.py", line 57, in ensure_schema
    raise MigrationSchemaMissing("Unable to create the django_migrations table (%s)" % exc)
django.db.migrations.exceptions.MigrationSchemaMissing: Unable to create the django_migrations table (no schema has been selected to create in
LINE 1: CREATE TABLE "django_migrations" ("id" serial NOT NULL PRIMA...
                     ^
)

I tried running these GRANT statements suggested here:

grant usage on schema public to <username>;  
grant create on schema public to <username>;

But I still get the same message. Any ideas how I can fix this? Is it a search_path issue maybe?

Update

~ python manage.py makemigrations users
Migrations for 'users':
  users\migrations\0001_initial.py
    - Create model MyUser

~ python manage.py migrate
Operations to perform:
  Apply all migrations: auth, contenttypes, sessions, users
Running migrations:
  No migrations to apply.

I tried the makemigrations before doing the migrate (duh!), but I still get the same error as before. Did the migrations even get applied? I should also mention that my models.py only has one model/table and it is not "managed" by Django.

Bueller...Bueller...Beuller...Anyone?

Answer 1

I ran into the same error and then solved it. In my case, I believe it is because that I set Django default schema to django, when running $ python manage.py test, the test function tried to migrate some tables to database test schema django, however schema django hadn't been created there yet. So the solution is either (1) to allow Django test function to search in schema public as well, or (2) to run unit test without a test database.

Judging from the accepted answer to this question, I guess my case is different from the question's. But I think both were caused by Django being not able to find schema in the search path. Hence I posted my solution here. Hope it might help similar situations.

(django-tally-QTYVOJb0) (python3.6) D:\github\django-tally>python manage.py test
Creating test database for alias 'default'...
Got an error creating the test database: database "test" already exists

Type 'yes' if you would like to try deleting the test database 'test', or 'no' to cancel: yes
Destroying old test database for alias 'default'...
Traceback (most recent call last):
  File "C:\Users\guido\.virtualenvs\django-tally-QTYVOJb0\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql)
psycopg2.errors.InvalidSchemaName: no schema has been selected to create in
LINE 1: CREATE TABLE "django_migrations" ("id" serial NOT NULL PRIMA...

For solution (1): The database settings in settings.py looked like this before.

if 'RDS_HOSTNAME' in os.environ:
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': os.environ['RDS_DB_NAME'],
            'USER': os.environ['RDS_USERNAME'],
            'PASSWORD': os.environ['RDS_PASSWORD'],
            'HOST': os.environ['RDS_HOSTNAME'],
            'PORT': os.environ['RDS_PORT'],
            'OPTIONS': {
                'options': '-c search_path=django'
            },
            'TEST': {
                'NAME': 'test', # test database name
            },
        },
    }

It looks like this now. I added public to the search path.

if 'RDS_HOSTNAME' in os.environ:
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': os.environ['RDS_DB_NAME'],
            'USER': os.environ['RDS_USERNAME'],
            'PASSWORD': os.environ['RDS_PASSWORD'],
            'HOST': os.environ['RDS_HOSTNAME'],
            'PORT': os.environ['RDS_PORT'],
            'OPTIONS': {
                'options': '-c search_path=django,public'
            },
            'TEST': {
                'NAME': 'test', # test database name
            },
        },
    }

Answer 2

For same error I did something different, well not different but I directly went to psql server(in my case). It happend during the development. So, I was not concious about possible data losses. Select your database. Then, create schema.

CREATE SCHEMA public;
GRANT ALL ON SCHEMA public TO postgres;
GRANT ALL ON SCHEMA public TO public;

I got the answer from https://stackoverflow.com/a/13823560/10860596. As, I got problem because I dropped all tables.

Answer 3

I think its loo late to answer but what work for me is just simple follow following steps:

1) open the pg admin application 
2)open the database you created
3)you will see schemas and then right click on it and create the schemas and named it as public then save.
4)then migrate the table from command line you will see migrations