Question

I have been trying since this morning and have read all the posts here and all over about accessing multiple databases in django with no avail. I m looking to access another database on the same server and I have included the databases in the settings.py with aliases. When I m trying to use the using() in the queryset I m getting an error that the Global name ‘Objectname’ does not exists. I m using postgresql 9.1 with django 1.4

Is there anything that I need to import for this to work? Its not working for me either in the console (python manage.py shell) or the views.

Here is the database setup from settings.py:

DATABASES = {
 'default': {
    'ENGINE': 'django.db.backends.postgresql_psycopg2',     # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
    'NAME': 'testing',      # Or path to database file if using sqlite3.
    'USER': 'xxxx',                     # Not used with sqlite3.
    'PASSWORD': 'xxxx',                 # Not used with sqlite3.
    'HOST': 'localhost',                    # Set to empty string for localhost. Not used with sqlite3.
    'PORT': 'xxxx',                         # Set to empty string for default. Not used with sqlite3.
},
'app_data': {
    'ENGINE': 'django.db.backends.postgresql_psycopg2',     # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
    'NAME': 'applications',      # Or path to database file if using sqlite3.
    'USER': 'xxxx',                     # Not used with sqlite3.
    'PASSWORD': 'xxxx',                 # Not used with sqlite3.
    'HOST': 'localhost',                    # Set to empty string for localhost. Not used with sqlite3.
    'PORT': 'xxxx',                         # Set to empty string for default. Not used with sqlite3.
},
'ppp_data': {
    'ENGINE': 'django.db.backends.postgresql_psycopg2',     # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
    'NAME': 'platform',      # Or path to database file if using sqlite3.
    'USER': 'xxxx',                     # Not used with sqlite3.
    'PASSWORD': 'xxxx',                 # Not used with sqlite3.
    'HOST': 'localhost',                    # Set to empty string for localhost. Not used with sqlite3.
    'PORT': 'xxxx',                         # Set to empty string for default. Not used with sqlite3.
}

}

Here is the code from the console:

>>> MyModel.objects.using('app_data').all()
Traceback (most recent call last):
File "<console>", line 1, in <module>
NameError: name 'MyModel' is not defined

Here is the error from the view:

NameError at /myapp/view
global name 'MyModel' is not defined

Please help!

Edited: Just to give a little background I have 3 different apps running on one server with different databases and I wanted to access records across different apps just for viewing.
The 3 apps are app, ppp and testing and I m trying to access app and ppp data from my testing app.

Answer 1

I had to append the app paths for other apps to the wsgi file.

import os, sys
sys.path.append('/opt/www/test')
sys.path.append('/opt/www/app')
sys.path.append('/opt/www/ppp')

Then I could import the models from other apps

from pp_app.myapp.models import MyModel
from pp_ppp.myapp.models import MyModel

Then this allowed me to use the using() method in the views to get the records:

data1 = MyModel.objects.using('app_data').all() 
data2 = MyModel.objects.using('ppp_data').all() 

Hope this helps someone else.