Django ValueError：'dteclared with a lazy reference to .....' 更改模型名称时

Question

这是我创建的第一个模型

class IPAddresses(models.Model):
    '''
    @brief      Class for ip addresses.
    @attrs      name        Can be company name
    '''

    ip = models.GenericIPAddressField()
    name = models.CharField(max_length=150, null=True, blank=True)
    active = models.BooleanField(default=True)

    def __unicode__(self):
        return self.ip



class Authentication(models.Model):
    '''
    @brief      Custom Authentication for dashboard
    @attrs      name    can be a name of a person
    '''


    name = models.CharField(max_length=100, null=True, blank=True)
    password = models.CharField(max_length=200, unique=True)
    ip = models.ManyToManyField(IPAddresses, blank=True)

但是，我将“IPAddresses”的模型名称更改为“IPAddress”并运行迁移。很好，但是我的下一次迁移不是，并且一直收到此值错误：

  Apply all migrations: admin, auth, cache_admin, contenttypes, core, provider, saba_dashboard, sessions
Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/deanchristianarmada/Desktop/projects/asian_gaming/radar/lib/python2.7/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
    utility.execute()
  File "/Users/deanchristianarmada/Desktop/projects/asian_gaming/radar/lib/python2.7/site-packages/django/core/management/__init__.py", line 359, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/deanchristianarmada/Desktop/projects/asian_gaming/radar/lib/python2.7/site-packages/django/core/management/base.py", line 294, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/deanchristianarmada/Desktop/projects/asian_gaming/radar/lib/python2.7/site-packages/django/core/management/base.py", line 345, in execute
    output = self.handle(*args, **options)
  File "/Users/deanchristianarmada/Desktop/projects/asian_gaming/radar/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 164, in handle
    pre_migrate_apps = pre_migrate_state.apps
  File "/Users/deanchristianarmada/Desktop/projects/asian_gaming/radar/lib/python2.7/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/Users/deanchristianarmada/Desktop/projects/asian_gaming/radar/lib/python2.7/site-packages/django/db/migrations/state.py", line 176, in apps
    return StateApps(self.real_apps, self.models)
  File "/Users/deanchristianarmada/Desktop/projects/asian_gaming/radar/lib/python2.7/site-packages/django/db/migrations/state.py", line 249, in __init__
    raise ValueError("\n".join(error.msg for error in errors))
ValueError: The field saba_dashboard.Authentication.ip was declared with a lazy reference to 'core.ipaddresses', but app 'core' doesn't provide model 'ipaddresses'.
The field saba_dashboard.Authentication_ip.ipaddresses was declared with a lazy reference to 'core.ipaddresses', but app 'core' doesn't provide model 'ipaddresses'.

我该如何解决？

我正在使用：

Django 1.10.5
Postgresql
Python 2.7

Answer 1

我自己一直在为这样的僵局而苦苦挣扎，不断收到“ValueError：该字段...被声明为对'...'的懒惰引用，但应用程序'...'不提供模型'...'。 ”。

在深入 pgadmin 并删除/恢复一些表后，我实际上发现它也可以通过添加一个新的迁移来解决，该迁移告诉 django 引用的模型已更改：

    migrations.AlterField(
        model_name='...',
        name='...',
        field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='...', to='<app>.<new-model>'), <===
    ),

此外，我必须正确设置应用程序之间的依赖关系，因此例如 AlterField 显然应该依赖于创建该模型的迁移。不要问我为什么它不能开箱即用，我只是不得不经历这个......

保罗