Django.db.utils.ConnectionDoesNotExist: The connection default doesn't exist

Question

I'm trying to connect the mongo(v4.0.3)db with django(v1.11) using mongoengine(0.6.0) driver. It is showing connection does not exist.

my settings.py file is as follows:

import os

import mongoengine

dbname = 'newdb'

mongoengine.connect(dbname, host='127.0.0.1', port = 27017)

BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

SECRET_KEY = ''

DEBUG = True

ALLOWED_HOSTS = []


INSTALLED_APPS = [

    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'mdbcapp',
 ]

 MIDDLEWARE = [

    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
 ]

 ROOT_URLCONF = 'multiple_databses_connections.urls'

 TEMPLATES = [

    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
 ]

 WSGI_APPLICATION = 'multiple_databses_connections.wsgi.application'

 DATABASES = {

    'dfault': {
        'ENGINE': '',
        'NAME'  : ''
       }


 AUTH_PASSWORD_VALIDATORS = [

    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },


LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True

STATIC_URL = '/static/'

I'm getting following errors:

Traceback (most recent call last):

File "manage.py", line 22, in execute_from_command_line(sys.argv) File "/usr/local/lib/python2.7/dist-packages/django/core/management/init.py", line 363, in execute_from_command_line utility.execute() File "/usr/local/lib/python2.7/dist-packages/django/core/management/init.py", line 337, in execute django.setup() File "/usr/local/lib/python2.7/dist-packages/django/init.py", line 27, in setup apps.populate(settings.INSTALLED_APPS) File "/usr/local/lib/python2.7/dist-packages/django/apps/registry.py", line 108, in populate app_config.import_models() File "/usr/local/lib/python2.7/dist-packages/django/apps/config.py", line 202, in import_models self.models_module = import_module(models_module_name) File "/usr/lib/python2.7/importlib/init.py", line 37, in import_module import(name) File "/usr/local/lib/python2.7/dist-packages/django/contrib/auth/models.py", line 4, in from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager File "/usr/local/lib/python2.7/dist-packages/django/contrib/auth/base_user.py", line 52, in class AbstractBaseUser(models.Model): File "/usr/local/lib/python2.7/dist-packages/django/db/models/base.py", line 124, in new new_class.add_to_class('_meta', Options(meta, app_label)) File "/usr/local/lib/python2.7/dist-packages/django/db/models/base.py", line 330, in add_to_class value.contribute_to_class(cls, name) File "/usr/local/lib/python2.7/dist-packages/django/db/models/options.py", line 214, in contribute_to_class self.db_table = truncate_name(self.db_table, connection.ops.max_name_length()) File "/usr/local/lib/python2.7/dist-packages/django/db/init.py", line 33, in getattr return getattr(connections[DEFAULT_DB_ALIAS], item) File "/usr/local/lib/python2.7/dist-packages/django/db/utils.py", line 208, in getitem self.ensure_defaults(alias) File "/usr/local/lib/python2.7/dist-packages/django/db/utils.py", line 178, in ensure_defaults raise ConnectionDoesNotExist("The connection %s doesn't exist" % alias) django.db.utils.ConnectionDoesNotExist: The connection default doesn't exist

How do I solve the problem?

Answer 1

You are using only the Mongo engine. But in the settings file, the database ENGINE key is mandatory. Add this line in ENGINE:

DATABASES = {
    'default': {
        'ENGINE': 'django.core.cache.backends.dummy.DummyCache',
        'NAME': 'mydatabase',
     }
}

But it may throw an error like database improperly configured which is ignorable.

For more information ref link https://docs.djangoproject.com/en/dev/ref/settings/#backend

Answer 2

Default settings for Sqlite

DATABASES = {
'default': {
    'ENGINE': 'django.db.backends.sqlite3',
    'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
 }
}

Settings for MySQL

DATABASES = {
'default': {
    'ENGINE': 'django.db.backends.mysql',
    'NAME': 'my_db_name',
    'USER': 'root',
    'PASSWORD': '',
    'HOST':'localhost',
    'PORT':'3306'
  }
 }