Django迁移报错：oauth2_provider字段引用未安装的apis应用

环境信息 #

• Django版本：4.0.6
• django-oauth-toolkit版本：2.2.0

项目结构 #

accs
cms
apis
    migrations
    models
        __init__.py
        custom_application.py
    static
    templates
    views
    __init__.py
    apps.py
    urls.py
owner
sonline
tnt

自定义Application模型代码（apis/models/custom_application.py） #

from django.db import models
from oauth2_provider.models import AbstractApplication

from tnt.models import TntModel


class CustomApplicationModel(AbstractApplication):
    tnt = models.ForeignKey(TntModel, on_delete=models.CASCADE)

    class Meta(AbstractApplication.Meta):
        pass

项目配置（sonline/settings.py） #

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'django.contrib.humanize',
    'cms',
    'accs',
    'tnt',
    'owner',
    'rest_framework',
    'background_task',
    'apis',
    'oauth2_provider',
]

# OAUTH2 settings
OAUTH2_PROVIDER = {
    'ACCESS_TOKEN_EXPIRE_SECONDS': 604800
}

OAUTH2_PROVIDER_APPLICATION_MODEL = 'apis.CustomApplicationModel'

错误场景及日志 #

执行makemigrations成功生成apis的迁移文件，但执行migrate时报错：

(venv) PS D:\s> python .\manage.py makemigrations
Migrations for 'apis':
  apis\migrations\0001_initial.py
    - Create model CustomApplicationModel
(venv) PS D:\s> python .\manage.py migrate       
Operations to perform:
  Apply all migrations: accs, admin, auth, background_task, cms, contenttypes, oauth2_provider, apis, sessions, tnt
Traceback (most recent call last):
  File "D:\s\manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "D:\venv\lib\site-packages\django\core\management\__init__.py", line 446, in execute_from_command_line
    utility.execute()
  File "D:\venv\lib\site-packages\django\core\management\__init__.py", line 440, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "D:\venv\lib\site-packages\django\core\management\base.py", line 414, in run_from_argv
    self.execute(*args, **cmd_options)
  File "D:\venv\lib\site-packages\django\core\management\base.py", line 460, in execute
    output = self.handle(*args, **options)
  File "D:\venv\lib\site-packages\django\core\management\base.py", line 98, in wrapped
    res = handle_func(*args, **kwargs)
  File "D:\venv\lib\site-packages\django\core\management\commands\migrate.py", line 236, in handle
    pre_migrate_apps = pre_migrate_state.apps
  File "D:\venv\lib\site-packages\django\utils\functional.py", line 49, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "D:\venv\lib\site-packages\django\db\migrations\state.py", line 544, in apps
    return StateApps(self.real_apps, self.models)
  File "D:\venv\lib\site-packages\django\db\migrations\state.py", line 615, in __init__
    raise ValueError("\n".join(error.msg for error in errors))
ValueError: The field oauth2_provider.AccessToken.application was declared with a lazy reference to 'apis.customapplicationmodel', but app 'apis' isn't installed.    
The field oauth2_provider.Grant.application was declared with a lazy reference to 'apis.customapplicationmodel', but app 'apis' isn't installed.
The field oauth2_provider.IDToken.application was declared with a lazy reference to 'apis.customapplicationmodel', but app 'apis' isn't installed.
The field oauth2_provider.RefreshToken.application was declared with a lazy reference to 'apis.customapplicationmodel', but app 'apis' isn't installed.

解决方案 #

1. 确保自定义模型被Django识别 #

编辑apis/models/__init__.py，导入自定义模型：

from .custom_application import CustomApplicationModel

Django需要从apis.models路径下读取到该模型，否则会判定模型不存在。

2. 重置并重新生成迁移文件 #

删除已生成的apis迁移文件（apis/migrations/0001_initial.py），然后重新生成：

python manage.py makemigrations apis

3. 优先执行apis应用的迁移 #

先创建自定义Application模型对应的表，避免oauth2_provider迁移时找不到依赖：

python manage.py migrate apis

4. 执行全局迁移 #

此时oauth2_provider的迁移可以正常引用已创建的CustomApplicationModel：

python manage.py migrate

额外处理（若之前执行过oauth2_provider迁移） #

如果数据库中已有oauth2_provider的旧表结构，需要先回滚其迁移记录：

python manage.py migrate oauth2_provider zero

再按上述步骤重新执行迁移。

内容的提问来源于stack exchange，提问作者Remus Case