python - Django 模型字段名称 "check"引发 SystemCheckError

Question

Django docs声明对模型字段名称只有两个限制

• 字段名不能是 Python 保留字
• 一个字段名不能连续包含一个以上的下划线

但是，在下面的示例中，我似乎无法将字段名称 check 用作 ForeignKey。

class Check(models.Model):

    name = models.CharField(max_length=100)

class MyModel(models.Model):

    # this works fine
    #check = models.BooleanField()

    # this breaks
    check = models.ForeignKey(Check, on_delete=models.PROTECT, related_name='+')

这是错误:

$ python manage.py check
SystemCheckError: System check identified some issues:

ERRORS:
myapp.MyModel: (models.E020) The 'MyModel.check()' class method is currently overridden by <django.db.models.fields.related_descriptors.ForwardManyToOneDescriptor object at 0x03A818D0>

是文档错了，还是我做错了什么？

编辑:忘了说这个项目使用的是 Python 2 和 Django 1.11

Answer 1

我在 django 文档中找到了系统检查框架 ( https://docs.djangoproject.com/en/2.2/ref/checks/#system-check-framework )

在 django 的系统检查期间调用的检查字段引发了 SystemCheckError。

它发生在 django 的 Basecommand ( https://github.com/django/django/blob/1e87c9fe71703fab23039aa63fafe4f6aac98bbc/django/core/management/base.py#L148 )

1. ``django-admin`` or ``manage.py`` loads the command class
   and calls its ``run_from_argv()`` method.
2. The ``run_from_argv()`` method calls ``create_parser()`` to get
   an ``ArgumentParser`` for the arguments, parses them, performs
   any environment changes requested by options like
   ``pythonpath``, and then calls the ``execute()`` method,
   passing the parsed arguments.
3. The ``execute()`` method attempts to carry out the command by
   calling the ``handle()`` method with the parsed arguments; any
   output produced by ``handle()`` will be printed to standard
   output and, if the command is intended to produce a block of
   SQL statements, will be wrapped in ``BEGIN`` and ``COMMIT``.
4. If ``handle()`` or ``execute()`` raised any exception (e.g.
   ``CommandError``), ``run_from_argv()`` will  instead print an error
   message to ``stderr``.