python - 测试用例中缺少 ROLLBACK 会导致多数据库 django 应用程序中出现唯一约束冲突

Question

我才刚刚开始使用 factory_boy用于测试工厂的 django 库，并且存在重复键约束违规问题。

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()

工厂.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())

---

运行第一个测试成功，但第二个测试失败并出现以下错误:

IntegrityError: duplicate key value violates unique constraint "country_of_origin_code_key"

我的理解是每个测试用例都应该在一个事务中运行，但是在第二次测试运行之前外键的创建似乎没有回滚。显然我在做一些根本错误的事情，但我有点难过!谢谢!

---

我已经找到问题所在，但不幸的是不知道如何解决。问题是回滚正在发生，但只发生在一个数据库上(此应用程序有 2 个数据库)。由于遗留原因，我们为 django 身份验证、平面页面等提供了一个单独的数据库，为我们的应用程序提供了另一个数据库。

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"

---

有类似问题的人here .

Answer 1

Django 有有support for testing against multiple databases从 1.2 开始!

将以下属性添加到我的 TestCase 解决了这个问题:

multi_db = True