如何解决此django OneToOneField模型错误？

问题描述

我正在尝试创建一个模型，该模型需要与大量公式所使用的原料之间一对一的关系。这是我的代码：

from django.db import models
from dashboard.models import Formulas,Feedstock

class FeedstockFormulas(models.Model):
    ratio = models.FloatField()
    Feedstock = models.OnetoOneField(Feedstock,on_delete=models.CASCADE,default="0")
    formulas = models.ForeignKey(Formulas,on_delete=models.CASCADE)

这是我得到的错误：

Traceback (most recent call last):
  File "/home/isaacrpl7/.local/lib/python3.8/site-packages/django/db/models/fields/related.py",line 798,in __init__
    to._Meta.model_name
AttributeError: module 'dashboard.models.Feedstock' has no attribute '_Meta'

During handling of the above exception,another exception occurred:

Traceback (most recent call last):
  File "manage.py",line 22,in <module>
    execute_from_command_line(sys.argv)
  File "/home/isaacrpl7/.local/lib/python3.8/site-packages/django/core/management/__init__.py",line 401,in execute_from_command_line
    utility.execute()
  File "/home/isaacrpl7/.local/lib/python3.8/site-packages/django/core/management/__init__.py",line 377,in execute
    django.setup()
  File "/home/isaacrpl7/.local/lib/python3.8/site-packages/django/__init__.py",line 24,in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/isaacrpl7/.local/lib/python3.8/site-packages/django/apps/registry.py",line 114,in populate
    app_config.import_models()
  File "/home/isaacrpl7/.local/lib/python3.8/site-packages/django/apps/config.py",line 211,in import_models
    self.models_module = import_module(models_module_name)
  File "/usr/lib/python3.8/importlib/__init__.py",line 127,in import_module
    return _bootstrap._gcd_import(name[level:],package,level)
  File "<frozen importlib._bootstrap>",line 1014,in _gcd_import
  File "<frozen importlib._bootstrap>",line 991,in _find_and_load
  File "<frozen importlib._bootstrap>",line 975,in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>",line 671,in _load_unlocked
  File "<frozen importlib._bootstrap_external>",line 783,in exec_module
  File "<frozen importlib._bootstrap>",line 219,in _call_with_frames_removed
  File "/mnt/c/Users/isaac/Documents/Github/uniaoracoes/dashboard/models/__init__.py",line 1,in <module>
    from .Formulas import Formulas
  File "/mnt/c/Users/isaac/Documents/Github/uniaoracoes/dashboard/models/Formulas.py",line 2,in <module>
    from dashboard.models import FeedstockFormulas
  File "/mnt/c/Users/isaac/Documents/Github/uniaoracoes/dashboard/models/FeedstockFormulas.py",line 4,in <module>
    class FeedstockFormulas(models.Model):
  File "/mnt/c/Users/isaac/Documents/Github/uniaoracoes/dashboard/models/FeedstockFormulas.py",line 6,in FeedstockFormulas
    Feedstock = models.OnetoOneField(Feedstock,default="0")
  File "/home/isaacrpl7/.local/lib/python3.8/site-packages/django/db/models/fields/related.py",line 1049,in __init__
    super().__init__(to,on_delete,to_field=to_field,**kwargs)
  File "/home/isaacrpl7/.local/lib/python3.8/site-packages/django/db/models/fields/related.py",line 800,in __init__
    assert isinstance(to,str),(
AssertionError: OnetoOneField(<module 'dashboard.models.Feedstock' from '/mnt/c/Users/isaac/Documents/Github/uniaoracoes/dashboard/models/Feedstock.py'>) is invalid. First parameter to ForeignKey must be either a model,a model name,or the string 'self'

我无法真正解决它，因为ForeignKey的第一个参数已经是模型...

解决方法

这似乎是某处循环进口的副产品。

尝试更改为

feedstock = models.OneToOneField("dashboard.Feedstock",on_delete=models.CASCADE,default="0")
formulas = models.ForeignKey("dashboard.Formulas",on_delete=models.CASCADE)