Question

I’m just getting started with the factory_boy django library for test factories, and having an issue with a duplicate key constraint violation.

test_member_programme.py

from datetime import date, timedelta

from django.test import TestCase

from app.test.factories import MemberFactory, ProgrammeFactory
from app.models.member_programme import MemberProgramme


class MemberProgrammeTestCase(TestCase):

    def member_programme(self):
        yesterday = date.today() - timedelta(days=1)
        return MemberProgramme.objects.create(
                mem=MemberFactory(),
                prg=ProgrammeFactory(),
                date_registered=yesterday)

    def date_registered_should_be_defined_test(self):
        # This test passes
        memprg = self.member_programme()
        assert hasattr(memprg, 'date_registered')

    def date_registered_should_be_in_past_test(self):
        # This test fails
        memprg = self.member_programme()
        assert memprg.date_registered < date.today()

factories.py

class CountryOfOriginFactory(factory.Factory):
    """ Factory class for app.models.CountryOfOrigin
    """
    FACTORY_FOR = CountryOfOrigin

    code = 'UK'
    the_country = 'United Kingdom'

class MemberFactory(factory.Factory):
    """ Factory class for app.models.Member
    """
    FACTORY_FOR = Member

    first_name = 'Test'
    surname = 'User'
    sex = 'M'
    date_of_birth = datetime.date(1990, 1, 1)
    origin = factory.LazyAttribute(lambda a: CountryOfOriginFactory())

---

When running the first test passes successfully, but the second fails with the following error:

IntegrityError: duplicate key value violates unique constraint "country_of_origin_code_key"

My understanding is that every TestCase should run within a transaction, yet the creation of the foreign key does not appear to have rolled back before the second test runs. Clearly I’m doing something fundamentally wrong, but I’m a bit stumped! Thanks!

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I’ve tracked down the problem, but unfortunately don’t know how to resolve it. The issue is that ROLLBACKs are occurring, but only on one database (this app has 2 databases). For legacy reasons, we have a separate database for django auth, flatpages etc and another db for our app.

dba test_app 127.0.0.1 2012-09-04 21:51:50.806 UTC LOG:  duration: 0.038 ms  statement: BEGIN; SET TRANSACTION ISOLATION LEVEL READ COMMITTED
dba test_app 127.0.0.1 2012-09-04 21:51:50.808 UTC LOG:  duration: 0.903 ms  statement: INSERT INTO "member_programme" ("mem_id", "prgm_id", "date_registered", "date_completed", "ordinality") VALUES (1, 1, E'2012-09-04', NULL, 1)
dba test_app 127.0.0.1 2012-09-04 21:51:50.808 UTC LOG:  duration: 0.150 ms  statement: SELECT CURRVAL(pg_get_serial_sequence('"member_programme"','id'))
dba test_app 127.0.0.1 2012-09-04 21:51:50.810 UTC LOG:  duration: 1.796 ms  statement: COMMIT
dba test_app_django 127.0.0.1 2012-09-04 21:51:50.811 UTC LOG:  duration: 0.056 ms  statement: ROLLBACK <---- ROLLBACK ON DJANGO DB ONLY
dba test_app_django 127.0.0.1 2012-09-04 21:51:50.814 UTC LOG:  disconnection: session time: 0:00:21.005 user=dba database=test_app_django host=127.0.0.1 port=60355
dba test_app 127.0.0.1 2012-09-04 21:51:50.818 UTC LOG:  disconnection: session time: 0:00:04.751 user=dba database=test_app host=127.0.0.1 port=60357
dba test_app 127.0.0.1 2012-09-04 21:54:00.796 UTC LOG:  connection authorized: user=dba database=test_app
dba test_app 127.0.0.1 2012-09-04 21:54:00.802 UTC LOG:  duration: 0.243 ms  statement: SET DATESTYLE TO 'ISO'
dba test_app 127.0.0.1 2012-09-04 21:54:00.802 UTC LOG:  duration: 0.156 ms  statement: SHOW client_encoding
dba test_app 127.0.0.1 2012-09-04 21:54:00.803 UTC LOG:  duration: 0.047 ms  statement: SHOW default_transaction_isolation
dba test_app 127.0.0.1 2012-09-04 21:54:00.803 UTC LOG:  duration: 0.068 ms  statement: BEGIN; SET TRANSACTION ISOLATION LEVEL READ COMMITTED
dba test_app 127.0.0.1 2012-09-04 21:54:00.804 UTC LOG:  duration: 0.410 ms  statement: SET TIME ZONE E'Pacific/Auckland'
dba test_app 127.0.0.1 2012-09-04 21:54:00.805 UTC ERROR:  duplicate key value violates unique constraint "country_of_origin_code_key"

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Someone with a similar problem here.

Answer 1

Django has had support for testing against multiple databases since 1.2!

Adding the following property to my TestCase resolved the issue:

multi_db = True