Test Case on Models - I'm stuck

Recently written test case for an API model - and it worked fine on the API. I used the structure of the test case on a database model, but I’m getting a FAIL.

Running the app locally works fine, there are no issues, but his test case isn’t working. Any advice on how to get “un stuck” is greatly appreciated!

from django.test import SimpleTestCase
from django.urls import reverse

from .models import Post 

class PostObjectTest(SimpleTestCase):
    def setUpTestData(cls):
        cls.post = Post.objects.create(
            title="Post Short Description",
            description="Long description of job post",

    def test_listview(self):
        response = self.client.get(reverse("post_list"))    # Check that correct URL is being used
        self.assertEqual(response.status_code, 200)         # Confirm 200 status
        self.assertEqual(Post.objects.count(), 1)           # Confirm single entry
        self.assertContains(response, self.post)            # Confirm all data created Post object
Found 2 test(s).
Creating test database for alias 'default'...
System check identified no issues (0 silenced).
FAIL: test_listview (posts.tests.PostObjectTest)

You’ve got three asserts in test_listview, it would be helpful to know which of those three are failing. I would have expected that the test output contains that information?

django.test.testcases.DatabaseOperationForbidden: Database queries to 'default' are not allowed in SimpleTestCase subclasses. Either subclass TestCase or TransactionTestCase to ensure proper test isolation or add 'default' to posts.tests.PostObjectTest.databases to silence this failure.

Subclassing TestCase, instead of SimpleTestCase passed.