[Fixed]-Django runserver custom database

A cleaner and more scalable way to switch configurations than to create several config files would be to use environment variables (see #3 of the twelve-factor app methodology used by Heroku and others). For example:

from os import environ

DATABASES = {
    'main': {
        'NAME': 'db.db',
        'ENGINE': 'django.db.backends.sqlite3'
    },
    'tests': {
        'NAME': 'tests.db',
        'ENGINE': 'django.db.backends.sqlite3'
    },
}

default_database = environ.get('DJANGO_DATABASE', 'main')
DATABASES['default'] = DATABASES[default_database]

You can then change the default database by setting the DJANGO_DATABASE environment variable.

export DJANGO_DATABASE='tests'
./manage.py runserver

…or…

DJANGO_DATABASE='tests' ./manage.py runserver

You could also set environment variables using Python code.

Edit: To make this process easier, Kenneth Reitz has written a nice little app called dj-database-url.

Create settings_tests.py with following:

from settings import *

DATABASES = {
    'default': {
        'NAME': 'tests.db',
        'ENGINE': 'django.db.backends.sqlite3'
    },

}

Execute django-admin.py runserver --settings=settings_tests

@Danilo Barges put a simple way to solve the problem. I only add a few change to deal with running tests. That’s because DATABASES['default'] = DATABASES[default_database] will add an entry to DATABASES dictionary. So if you run tests the test runner will run against 'default' and the next entry in DATABASES. Use two dictionaries instead:

DATABASES_AVAILABLE = {
    'default': {
        'NAME': 'db.db',
        'ENGINE': 'django.db.backends.sqlite3'
    },
    'tests': {
        'NAME': 'tests.db',
        'ENGINE': 'django.db.backends.sqlite3'
    },
}

database = os.environ.get('DJANGO_DATABASE', 'main')
DATABASES = {
    'default': DATABASES_AVAILABLE[database]
}