多数据库和无管理模型测试用例失败

Question

我使用非托管（只读）模型设置mutlidb。这些模型没有迁移。我试着测试视图.py. 在sqlite3数据库中，测试表的这些模式没有创建一个导致测试用例失败的问题。 在视图.py我已经导入了未管理的（只读）模型，但是失败了。你知道吗

我已经跟踪了testTesting against unmanaged models的链接

提到多数据库设置

试验_跑步者.py你知道吗

from django.test.runner import DiscoverRunner


class DisableMigrations(object):
    def __contains__(self, item):
        return True

    def __getitem__(self, item):
        return None


class UnManagedModelTestRunner(DiscoverRunner):

    def setup_test_environment(self, *args, **kwargs):
        from django.apps import apps
        # app_name = apps.get_app_config('core_esp')
        self.unmanaged_models = [m for m in apps.get_models() if not m._meta.managed and m._meta.app_label is 'core_esp']
        for m in self.unmanaged_models:
            m._meta.managed = True
        super(UnManagedModelTestRunner, self).setup_test_environment(*args, **kwargs)

    def teardown_test_environment(self, *args, **kwargs):
        super(UnManagedModelTestRunner, self).teardown_test_environment(*args, **kwargs)
        # reset un managed models
        for m in self.unmanaged_models:
            m._meta.managed = False

你知道吗设置.py你知道吗

 if 'test' in sys.argv or 'test_coverage' in sys.argv: 
    DATABASES = {                                                       
        'default': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': 'db.sqlite3',
        },
        'test_db': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': 'db.sqlite3',
        }
    }

INSTALLED_APPS = ['test']
# Skip the migrations by setting "MIGRATION_MODULES"
# to the DisableMigrations class defined above
#
MIGRATION_MODULES = DisableMigrations()

# Set Django's test runner to the custom class defined above
TEST_RUNNER = 'apps.settings.test_runner.UnManagedModelTestRunner'
DATABASE_ROUTERS = ('apps.tests.test_dbrouter.TestApiRouter', )

你知道吗型号.py你知道吗

from django.db import models

class TestModelA(models.Model):
    testid = models.CharField(max_length=200)
    class Meta:
        managed = False
        db_table = 'TestD'

class TestModelB(models.Model):
    testid = models.CharField(max_length=200)
    class Meta:
        managed = False
        db_table = 'test_model_b'
        app_label = 'application_b'

你知道吗测试.py你知道吗

class MyTestCase(TestCase):

    def test_my_function(self):
       # view is called
       # serializer called with read only model
       pass

错误

Traceback (most recent call last):                                                                                 
File "C:\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql, params)                                                                                                                                   
File "C:\lib\site-packages\django\db\backends\sqlite3\base.py", line 383, in execute return Database.Cursor.execute(self, query, params)                                                                                                            
sqlite3.OperationalError: no such table: TestD 
The above exception was the direct cause of the following exception:                                                                                                                                              Traceback (most recent call last): 
File "manage.py", line 21, in <module> main() 
File "manage.py", line 17, in main execute_from_command_line(sys.argv)
File "C:\lib\site-packages\django\core\management\__init__.py", line 381, in execute_from_command_line utility.execute()
File "C:\lib\site-packages\django\core\management\__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\lib\site-packages\django\core\management\commands\test.py", line 23, in run_from_argv
super().run_from_argv(argv)
File "C:\lib\site-packages\django\core\management\base.py", line 323, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\lib\site-packages\django\core\management\base.py", line execute
output = self.handle(*args, **options)
File "C:\lib\site-packages\django\core\management\commands\test.py", line 53, in handle failures = test_runner.run_tests(test_labels)
File "C:\lib\site-packages\django\test\runner.py", line 627, in run_tests  
suite = self.build_suite(test_labels, extra_tests)
File "C:\lib\site-packages\django\test\runner.py", line 488, in build_suites   
tests = self.test_loader.loadTestsFromName(label)                                                                                                    
File "c:\program files\python37\Lib\unittest\loader.py", line 154, in loadTestsFromName 
module = __import__(module_name)                                                                                                                                           
File "C:\tests\tests.py", line 5, in <module>       
from .views import (                                                                                                                             
File "C:\views.py", line 6, in <module>    
from .serializers import (                                                                                                                       
File "C:\serializers.py", line 9, in <module>   
class TestSerializer(serializers.Serializer):                                                                                                                           
File "C:\serializers.py", line 13, in TestSerializer     
required=False, style={'base_template': 'select_multiple.html'}                                                                                                           
File "C:\lib\site-packages\rest_framework\fields.py", line 1476, in __init__                                                                      
super(MultipleChoiceField, self).__init__(*args, **kwargs)                                                                                                              
File "C:\lib\site-packages\rest_framework\fields.py", line 1417, in __init__                                                                         
self.choices = choices                                                                                                                        
File "C:\lib\site-packages\rest_framework\fields.py", line 1453, in _set_choices                                                                                                                                                                                                                         
for row in compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size):  
File "C:\lib\site-packages\django\db\models\sql\compiler.py", line 1052, in results_iter                                          
results = self.execute_sql(MULTI, chunked_fetch=chunked_fetch, chunk_size=chunk_size)                                       
File "C:\lib\site-packages\django\db\models\sql\compiler.py", line 1100, in execute_sql                                                             
cursor.execute(sql, params)                                                                                
File "C:\lib\site-packages\django\db\backends\utils.py", line 67, in execute 
return self._execute_with_wrappers(sql, params, many=False, 
executor=self._execute)
File "C:\lib\site-packages\django\db\backends\utils.py", line 76, in 
_execute_with_wrappers                                               
return executor(sql, params, many, context)                                                                                                                               
File "C:\lib\site-packages\django\db\backends\utils.py", line 84, in _execute                                                   
return self.cursor.execute(sql, params)                                                                                                                                   
File "C:\lib\site-packages\django\db\utils.py", line 89, in __exit__  
raise dj_exc_value.with_traceback(traceback) from exc_value           
File "C:\lib\site-packages\django\db\backends\utils.py", line 84, in _execute                                                                  
return self.cursor.execute(sql, params)                                                                                                                                   
File "C:\lib\site-packages\django\db\backends\sqlite3\base.py", line 383, in execute                                                                
return Database.Cursor.execute(self, query, params)                                                                                                                     
django.db.utils.OperationalError: no such table: TESTD

Answer 1

我可以告诉你我是如何解决这个问题的

所以我创造了一个信号，大致看起来是这样的：

def create_test_models(**kwargs):
    if "test" in sys.argv:
        Organization = apps.get_model("organizations.Organization")
        ...  # other models here too
        # as we do not manage it - we need to create it manually;
        with connection.schema_editor() as schema_editor:
            sid = transaction.savepoint()
            try:
                schema_editor.create_model(Organization)
                ... # different models here if needed
                transaction.savepoint_commit(sid)
            except ProgrammingError:  # tables already exists;
                transaction.savepoint_rollback(sid)

此信号在配置中作为pre_migrate信号连接：

class OrganizationsConfig(AppConfig):
    name = "engine.organizations"

    def ready(self):
        # run after each migration; so each deploy, but this method can handle the
        # incremental updates.
        pre_migrate.connect(create_test_models, sender=self)

它也许不是超级解决方案-但它是工作的，你有在测试期间创建的模型，你可以玩他们或创建测试数据等

希望这能帮助你前进。你知道吗

Answer 2

我在当前的django 2.2中找到了一个很好的解决方案。与pytest django完美结合，但即使没有pytest，也可能可以工作。你知道吗

要使其工作，您需要：

1. 将项目拆分为两个django应用程序。一个将只包含非托管模型，另一个将包含其余的模型。不要在这两个应用程序中指定managed=False

2. 在设置.py在数据库中，您将有两个数据库，一个是默认数据库，另一个是外部数据库

3. 在具有设置的同一文件夹中，创建路由器.py并实现一个路由器，该路由器将根据应用程序标签路由到给定的数据库（cca 45行，包括您永远不会写入这些外部数据库的检查）。然后将此路由器添加到设置.py的路由器列表。你知道吗

在使用pytest运行测试时，它确实为没有migrations文件夹的应用程序创建了所有表