Django＆＃34;对未知应用程序的依赖＆＃34;即使app文件夹存在，也会出错

Question

我尝试运行manage.py runserver或manage.py makemigrations，但是当我这样做时，我收到了错误。错误是：ValueError：对未知应用程序的依赖：后端。

这里是完整的错误消息：

Benjamins-MacBook-Pro:package-backend benhsu$ python3 manage.py makemigrations
Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/__init__.py", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/base.py", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/commands/makemigrations.py", line 57, in handle
    loader = MigrationLoader(None, ignore_no_migrations=True)
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/loader.py", line 48, in __init__
    self.build_graph()
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/loader.py", line 243, in build_graph
    parent = self.check_key(parent, key[0])
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/loader.py", line 168, in check_key
    raise ValueError("Dependency on unknown app: %s" % key[0])
ValueError: Dependency on unknown app: backend

＆＃34;后端＆＃34;是我正在处理的应用，您可以在我的文件夹中看到它存在。这是我的文件夹结构：

这是我的settings.py文件的相关部分：

# Application definition

AUTH_USER_MODEL = 'backend.User'

INSTALLED_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
    'backend'
)

我不明白为什么它不能正常工作，因为后端应用程序存在于我的文件夹中。

我很感激任何帮助！

Answer 1

自custom User以来，您是否尝试使用AUTH_USER_MODEL = 'backend.User'模型？

所以你必须尝试这样。

 ./manage.py makemigrations backend

来自https://docs.djangoproject.com/en/1.7/topics/migrations/#s-custom-fields

Answer 2

我使用自定义user应用程序遇到了同样的错误。

我删除了：

• 所有migrations个文件夹
• 所有*.pyc个文件
• 所有__pycach__目录
• my sql lite db

然后我跑了

python manage.py syncdb

这就是诀窍