Cleaning up a database in django before every test method

Question

By default when Django runs against sqlite backend it creates a new in memory database for a test. That means for every class that derives from unittest.TestCase, I get a new database. Can this be changed so that it is cleared before every test method is run?

Example: I am testing a manager class that provides additional abstraction on top of Django persistent objects. The code looks more-less like that

class TestForManager(unittest.TestCase):
  def testAddingBlah(self):
    manager = Manager()
    self.assertEquals(manager.getBlahs(), 0)
    manager.addBlah(...)
    self.assertEquals(manager.getBlahs(), 1)

  def testAddingBlahInDifferentWay(self):
    manager = Manager()
    self.assertEquals(manager.getBlahs(), 0)
    manager.addBlahInDifferentWay(...)
    self.assertEquals(manager.getBlahs(), 1)

Now, the first assertion of second test fails, because the state of the database is preserved between test calls and there already is an instance of Blah in the database.

What version of django do you use? Because all current versions flush database on every test method call. — Alex Koshelev, Jan 12 '09 at 08:41

score 64 · Accepted Answer · edited Dec 10 '20 at 06:39

64

Use django.test.TestCase not unittest.TestCase. And it works in all major versions of Django!

edited Dec 10 '20 at 06:39

Stephen Kiningham

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answered Jan 12 '09 at 19:59

Marcin

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From my experience, this only cleans up the default database and your on your own to clean up any other databases. Whats the best way to clean up non-default databases? – Buttons840 Sep 30 '13 at 20:11
1

Seriously, this post just saved me an hour of messing around. Thank you. – SleepyCal Apr 18 '14 at 22:05
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Set `multi_db=True` to clean all databases (in case you're using more than one) – Eduardo Matos Apr 14 '15 at 11:50
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Never say "as always" - you're asking for trouble. :-) – Adam Donahue Mar 13 '17 at 21:14
Thanks, it was `unittest.TestCase` added by PyCharm. Works now with `django.test.TestCase`! – Ivan Rostovsky Sep 16 '19 at 13:48
Just to confirm, and provide a recent date, that this answer solved my issue too – Seb Feb 15 '23 at 11:22

score 2 · Answer 2 · answered Dec 14 '10 at 11:11

2

You can use the tearDown method. It will be called after your test is run. You can delete all Blahs there.

answered Dec 14 '10 at 11:11

Amandasaurus

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also notice that you can use ``setUp`` to set up the database before running the testcase. – youkaichao Oct 16 '18 at 13:19

score 1 · Answer 3 · answered Feb 21 '19 at 14:25

1

Make them in two different functions both are not test function. Finally call the dependent functions from one test function.

answered Feb 21 '19 at 14:25

Mamun Hasan

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Could you add some short sample that gives better insight into what you mean? – rudolf_franek Feb 21 '19 at 14:57
Please visit here for details https://stackoverflow.com/questions/39866805/django-rest-framework-unit-testing-database-issue/54809606#54809606 – Mamun Hasan Feb 21 '19 at 15:08
I'm sorry I meant you could improve your answer by linking and example. In other words your answer seems uncomplete to me. – rudolf_franek Feb 21 '19 at 15:14

S.Lott · Answer 4 · 2009-01-12T13:09:50.570

Why not do the following? This accomplishes what you need without a significant change to your code.

class TestOneForManager(unittest.TestCase):
  def testAddingBlah(self):
    manager = Manager()
    self.assertEquals(manager.getBlahs(), 0)
    manager.addBlah(...)
    self.assertEquals(manager.getBlahs(), 1)

class TestTwoForManager(unittest.TestCase):
  def testAddingBlahInDifferentWay(self):
    manager = Manager()
    self.assertEquals(manager.getBlahs(), 0)
    manager.addBlahInDifferentWay(...)
    self.assertEquals(manager.getBlahs(), 1)

Edit. The "reset on TestCase" feature gives you complete control.

Many test methods in a single TestCase are good when you have test cases that don't interfere with each other.
Few test methods in a single TestCase are good when you have test cases that interfere with each other.

You can choose which model applies to your tests by grouping your test methods in one or many TestCases. You have total and complete control.

Yeah, I know, I could do that. But it kinda looks weird. It seems good to keep tests for a single class under one unittest.TestCase. I was more looking for some solution that would tune Django to do the right thing. — Marcin, Jan 12 '09 at 13:00
"It seems good to keep tests for a single class under one unittest.TestCase" There's no compelling reason for this. The original unittest design had a single runTest method. One test per Case is fine. — S.Lott, Jan 12 '09 at 13:07

score 0 · Answer 5 · answered Jan 07 '19 at 07:04

0

For clearing non-default databases, add multi_db = True in the class

eg

class MyTestCase(django.test.TestCase)
    multi_db = True

    def test_one(self):
        self.assertTrue(True)

answered Jan 07 '19 at 07:04

vestronge

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Cleaning up a database in django before every test method

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