django foreignKey error 발생시 (작성중)

Traceback (most recent call last):

  File "manage.py", line 15, in <module>

    execute_from_command_line(sys.argv)

  File "C:\python\lib\site-packages\django\core\management\__init__.py", line 371, in execute_from_command_line

    utility.execute()

  File "C:\python\lib\site-packages\django\core\management\__init__.py", line 347, in execute

    django.setup()

  File "C:\python\lib\site-packages\django\__init__.py", line 24, in setup

    apps.populate(settings.INSTALLED_APPS)

  File "C:\python\lib\site-packages\django\apps\registry.py", line 112, in populate

    app_config.import_models()

  File "C:\python\lib\site-packages\django\apps\config.py", line 198, in import_models

    self.models_module = import_module(models_module_name)

  File "C:\python\lib\importlib\__init__.py", line 126, in import_module

    return _bootstrap._gcd_import(name[level:], package, level)

  File "<frozen importlib._bootstrap>", line 978, in _gcd_import

  File "<frozen importlib._bootstrap>", line 961, in _find_and_load

  File "<frozen importlib._bootstrap>", line 950, in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 655, in _load_unlocked

  File "<frozen importlib._bootstrap_external>", line 678, in exec_module

  File "<frozen importlib._bootstrap>", line 205, in _call_with_frames_removed

  File "C:\python\django\mysite2\polls\models.py", line 10, in <module>

    class Choice(models.Model):

  File "C:\python\django\mysite2\polls\models.py", line 11, in Choice

    question = models.ForeignKey(Question)

TypeError: __init__() missing 1 required positional argument: 'on_delete'

이 경우

    question = models.ForeignKey('Question', on_delete=models.CASCADE,)

와 같이 on_delete 넣어줘야함 특히 2.0 이상부터는

https://docs.djangoproject.com/en/1.11/ref/models/fields/#foreignkey

ForeignKey¶

class ForeignKey(to, on_delete, **options)[source]¶

A many-to-one relationship. Requires two positional arguments: the class to which the model is related and the on_delete option. (on_delete isn’t actually required, but not providing it gives a deprecation warning. It will be required in Django 2.0.)

To create a recursive relationship – an object that has a many-to-one relationship with itself – use models.ForeignKey('self',on_delete=models.CASCADE).

If you need to create a relationship on a model that has not yet been defined, you can use the name of the model, rather than the model object itself: