Mongoengine: ConnectionError: You have not defined a default connection

Question

In my new Django project I set up a MongoDB database and use mongoengine module
but I can’t properly access the dabase neither in shell nor in views.

"ConnectionError: You have not defined a default connection"

My settings.py includes the following:

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



import mongoengine
SESSION_ENGINE = 'mongoengine.django.sessions'
mongoengine.connect(_MONGODB_NAME, 'localhost:27017')
AUTHENTICATION_BACKENDS = (
       'mongoengine.django.auth.MongoEngineBackend',
        )

In models.py:

import mongoengine

from mongoengine import *
from myproject.settings import _MONGODB_NAME
mongoengine.connect(_MONGODB_NAME, 'localhost:27017')

Asked By: c24b

||

Source

Answer 1

To use django with MongoDB do not use the django package available on https://www.djangoproject.com and install other packages like mongoengine, if follow this process you will find lot of difficulties.

Rather you need to use the no@rel version of django that has been forked from djangoproject and added MongoDB support and I am sure it will make setup process and development process lot easier.

Follow this link to install and set up the django with MongoDB.
http://django-mongodb-engine.readthedocs.org/en/latest/topics/setup.html

One more thing you may find the error below, while setting up django.

“*Error on Django-nonrel and MongoDB: AutoField (default primary key) values must be strings representing an ObjectId on MongoDB (got u’1′ instead). Please make sure your SITE_ID contains a valid ObjectId string.*”

Follow this link to fix.

https://gist.github.com/ielshareef/2986459

Please let me know if you need any more help on this.

Answered By: Shanki

Answer 2

I have not tested this in-depth, but so far it worked for me:

mongoengine.connect('yourdb', alias='default')

Answered By: biodiv

Answer 3

In your settings.py file replace:

mongoengine.connect(_MONGODB_NAME, 'localhost:27017')

with the below code (notice the added ‘host=‘):

mongoengine.connect(_MONGODB_NAME, host='localhost:27017')

Answered By: NiKS001

Answer 4

You need to specify the mongodb database name and not _MONGODB_NAME. You also need to comment the DATABASE settings in the django.

#Database connection
class ConnectionError(Exception):
pass

from mongoengine import connect
try:
connected = connect("blogDatabase", "localhost")
if connected:
print("Mongoengine is connected")
except ConnectionError:
raise ConnectionError

Answered By: Brian

Mongoengine: ConnectionError: You have not defined a default connection

Question:

Answers:

One more thing you may find the error below, while setting up django.

Follow this link to fix.