Querying the database in a Django unit test

I am creating a web application which has a POST endpoint, that does two things:

1. Saves the POSTed data (a university review) in the database.
2. Redirects the user to an overview page.

Here is the code for it:

if request.method == 'POST':
    review = Review(university=university,
                    user=User.objects.get(pk=1),
                    summary=request.POST['summary'])

    review.save()

    return HttpResponseRedirect(reverse('university_overview', args=(university_id,)))

I haven’t yet implemented passing the user data to the endpoint, and that’s why I’m saving everything under the user with pk=1.

My test is as follows:

class UniversityAddReviewTestCase(TestCase):
    def setUp(self):
        user = User.objects.create(username="username", password="password", email="email")
        university = University.objects.create(name="Oxford University", country="UK", info="Meh", rating="9")
        Review.objects.create(university=university, summary="Very nice", user_id=user.id)
        Review.objects.create(university=university, summary="Very bad", user_id=user.id)

        new_review = {
            'summary': 'It was okay.'
        }

        self.response = Client().post('/%s/reviews/add' % university.id, new_review)

    def test_database_updated(self):
        self.assertEqual(len(Review.objects.all()), 3)

The result is this:

  File ".../core/views.py", line 20, in detail
    user=User.objects.get(pk=1),
  File ".../ENV/lib/python3.6/site-packages/django/db/models/manager.py", line 82, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File ".../ENV/lib/python3.6/site-packages/django/db/models/query.py", line 403, in get
    self.model._meta.object_name
django.contrib.auth.models.DoesNotExist: User matching query does not exist.

Why is this happening? I know the user I’m creating has a pk=1, as when I actually print it during the test it’s 1.

Answer

pk is defined by the database. Something could make it not equal to 1 in your test.

Try this in your setUp method

user = User.objects.create_user(
    username="username",
    password="password",
    email="[e-mail]",
    id=1
)
assert user.pk == 1