Multiple Database without Default

[Sammie S. Taunton]

Following the example on ​https://docs.djangoproject.com/en/1.10/topics/db/multi-db/

I created 2 databases, setup the routers in the example, and tested

Data being selected appears to be working however when trying to insert OR update I'm receiving the following error:

Performing system checks...

System check identified no issues (0 silenced).
January 24, 2017 - 21:33:54
Django version 1.10.5, using settings 'application.settings'
Starting development server at http://10.4.1.1:80/
Quit the server with CONTROL-C.
Internal Server Error: /en/employee/edit
Traceback (most recent call last):
  File "/usr/local/python/lib/python3.6/site-packages/django/core/handlers/exception.py", line 39, in inner
    response = get_response(request)
  File "/usr/local/python/lib/python3.6/site-packages/django/core/handlers/base.py", line 187, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/usr/local/python/lib/python3.6/site-packages/django/core/handlers/base.py", line 185, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/usr/local/python/lib/python3.6/site-packages/django/contrib/auth/decorators.py", line 23, in _wrapped_view
    return view_func(request, *args, **kwargs)
  File "/vhosts/admin-install/login/security/gacl.py", line 27, in _wrapper
    return view_func(request, *args, **kwargs)
  File "/vhosts/admin-install/employee/views.py", line 112, in edit
    result2 = ServiceEdit(request).edit(form.cleaned_data)
  File "/usr/local/python/lib/python3.6/contextlib.py", line 52, in inner
    with self._recreate_cm():
  File "/usr/local/python/lib/python3.6/site-packages/django/db/transaction.py", line 158, in __enter__
    if not connection.get_autocommit():
  File "/usr/local/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 365, in get_autocommit
    self.ensure_connection()
  File "/usr/local/python/lib/python3.6/site-packages/django/db/backends/dummy/base.py", line 21, in complain
    raise ImproperlyConfigured("settings.DATABASES is improperly configured. "
django.core.exceptions.ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.
[24/Jan/2017 21:33:58] "POST /en/employee/edit HTTP/1.1" 500 19406

This is caused by the empty 'default': {} database configuration. I copied the primary settings into the default area and now things are working. However, I'd prefer to not be forced into using the default setting, which from the documentation in a multi-db setup the default is not required to be filled out, only the key needs to be there (which is fine).

As an additional test I added print() statements to the DB Router definitions for db_for_read, db_for_write, allow_relation, and allow_migrate. This would allow me to see when the page is reloaded / submitted if the query is even passing through the router. Reads were in fact going to the router as expected, however insert/updates were not. No print statement, only the error message.

Read Test in DB Router:

Performing system checks...

System check identified no issues (0 silenced).
January 24, 2017 - 21:46:01
Django version 1.10.5, using settings 'application.settings'
Starting development server at http://10.4.1.1:80/
Quit the server with CONTROL-C.
TEST READ MESSAGE
[24/Jan/2017 21:46:03] "GET /en/employee/edit HTTP/1.1" 200 74622

So based on this, I can only assume the routing is not happening properly someplace.

I'm willing to try what is needed to help resolve this.

[Tim Graham]

Hi, in a case like this, it's better to ask for help on our support channels until you confirm you've identified a bug. For best results, please include a sample project that reproduces the issue. If you confirm that Django is at fault, please reopen with details. Thanks.