local_settings.py

# Since we need a syncdb on all the databases, before the tests can be
# runned successfully we need to execute
#
#  $ python manage.py syncdb
#  $ python manage.py syncdb --database=test
#
# otherwise will be errors like
#
#  'django.db.utils.DatabaseError: no such table: django_site'

DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': 'bla',
            'USER': 'foo'
            'PASSWORD': 'bar'
        },
        'test': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': 'only4test.sqlite'
        },
}

# http://stackoverflow.com/questions/4650509/different-db-for-testing-in-django
import sys
if 'test' in sys.argv:
    DATABASES['default'] = DATABASES['test'];