Different db for testing in Django? - django

Question

DATABASES = {
# 'default': {
# 'ENGINE': 'postgresql_psycopg2',
# ...
# }
# for unit tests
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': 'mydatabase'
}
}
I have two databases: one I'd like to use for unit tests, and one for everything else. Is it possible to configure this in Django 1.2.4?
(The reason I ask is because with postgresql I'm getting the following error:
foo#bar:~/path/$ python manage.py test
Creating test database 'default'...
Got an error creating the test database: permission denied to create database
Type 'yes' if you would like to try deleting the test database 'test_baz', or 'no' to cancel: yes
Destroying old test database...
Got an error recreating the test database: database "test_baz" does not exist
Why could I be getting this error? I guess I don't really care if I can always use SQLite for unit tests, as that works fine.)

Answer 1

In your settings.py (or local_settings.py):
import sys
if 'test' in sys.argv:
DATABASES['default'] = {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': 'mydatabase'
}

Answer 2

The way I handle this is through having multiple settings files, since I use that to maintain a set of common settings with modifications for each instance. It's a little more complicated to set up than some of the other solutions, but I needed to do it anyway because I was managing slightly different settings for local development, remote development, staging and production.
https://code.djangoproject.com/wiki/SplitSettings has a number of options for managing settings, and I've chosen a practice similar to the one described at https://code.djangoproject.com/wiki/SplitSettings#SimplePackageOrganizationforEnvironments
So, in my Django project directory, I have a settings folder that looks like this:
$ tree settings
settings
├── defaults.py
├── dev.py
├── dev.pyc
├── __init__.py
├── lettuce.py
├── travis.py
├── unittest.py
The common settings are in settings/defaults.py and I import these in my instance settings files. So settings/unittest.py looks like this:
from defaults import *
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': 'my_database',
}
}
Then, when I want to run tests, I just execute:
$ ./manage.py test --settings=settings.unittest
to use sqlite for testing. I'll use a different settings module if I want to use a different test runner or database configuration.

Answer 3

You can specify test database in settings.py. See
https://docs.djangoproject.com/en/3.0/topics/testing/overview/#the-test-database
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql',
'USER': 'mydatabaseuser',
'NAME': 'mydatabase',
'TEST': {
'NAME': 'mytestdatabase',
},
},
}

Answer 4

I solved this issue simply creating other settings constant DATABASES_AVAILABLE.
DATABASES_AVAILABLE = {
'main': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'nep',
'USER': 'user',
'PASSWORD': 'passwd',
'HOST': 'localhost',
},
'remote': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'nes_dev',
'USER': 'usr',
'PASSWORD': 'passwd',
'HOST': '200.144.254.136',
},
'sqlite': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
},
}
# This solves the problem with tests
# Define a system variable called DJANGO_DATABASE_TEST and set it to the
# the database you want
database = os.environ.get('DJANGO_DATABASE_TEST', 'main')
DATABASES = {
'default': DATABASES_AVAILABLE[database]
}

Answer 5

This accelerated dramatically test execution.
import sys
if 'test' in sys.argv:
DATABASES['default'] = {
'ENGINE': 'django.db.backends.sqlite3',
'TEST_CHARSET': 'UTF8', # if your normal db is utf8
'NAME': ':memory:', # in memory
'TEST_NAME': ':memory:', # in memory
}
DEBUG = False # might accelerate a bit
TEMPLATE_DEBUG = False
from django.core.management import call_command
call_command('syncdb', migrate=True) # tables don't get created automatically for me

Answer 6

Though this is already solved...
If your database for tests is just a normal DB:
I think you are not doing unit test since you rely in the database. Anyway, django contains a test type for that (not unitary): django.test.TestCase
You need to derive from django.test.TestCase instead of unittest.TestCase that will create a fresh rehershal database for you that will be destroyed when the test end.
There are interesting explanations/tips about testing with db in the following link
Testing Django Applications

Answer 7

If you have access to manually create the database, you could use django-nose as your TEST_RUNNER. Once installed, if you pass the following environment variable, it will not delete and re-create the database.
REUSE_DB=1 ./manage.py test
You can also add the following to settings.py so you don't have to write REUSE_DB=1 every time you want to run tests:
os.environ['REUSE_DB'] = "1"
Note: this will also leave all your tables in the databases which means test setup will be a little quicker, but you will have to manually update the tables (or delete and re-create the database yourself) when you change your models.

Answer 8

You can mirror your db by editing settings.py:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql',
'USER': 'mydatabaseuser',
'NAME': 'mydatabase',
'TEST': {
'MIRROR': 'default',
},
},
}

Answer 9

Why could I be getting this error?
Because of insufficient permissions. You can alter the user permissions by ALTER USER username CREATEDB; after running psql with superuser priviliges.
Example,
$ sudo su - postgres
$ psql
psql (9.3.18)
Type "help" for help.
postgres=# ALTER USER username CREATEDB;
ALTER ROLE

Answer 10

I had your same issue. I resolved it just adding in settings.py the TEST value in the database, available in my Django version 4.0.2, in this way:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql',
'HOST': host,
'NAME': name,
'TEST': {'NAME': 'test_db'},
'USER': user,
'PASSWORD': your_password,
}
}.
This temporary creates db with different name and the conflict is resolved.