Django：摆脱循环依赖 [英] Django: getting rid of circular dependency

问题描述

我有两个应用程序， commonapp 和 app1 。

I have two apps, commonapp and app1.

这里是来自django的 commonapp / models.py ：

Here's commonapp/models.py:

from django.db import models
#from app1.models import SpecificFields

# Create your models here.
class CommonFields(models.Model):
    a = models.IntegerField(default = 0)

    class Meta:
        abstract = True

class SomeFields(models.Model):
#    a = models.ForeignKey(SpecificFields)
    a = models.ForeignKey('app1.models.SpecificFields')

这里的 app1 / models.py ：

from django.db import models
from commonapp.models import CommonFields

# Create your models here.
class SpecificFields(CommonFields):
    a2 = models.IntegerField(default=0)

当我尝试从 app1 或 commonapp 运行SQL时，我收到以下错误： p>

When I try to run the SQL from either app1 or commonapp, I get the following error:

$ python manage.py sql commonapp
CommandError: One or more models did not validate:
commonapp.somefields: 'a' has a relation with model app1.models.SpecificFields,
which has either not been installed or is abstract.

我意识到这是循环依赖的问题。其他人建议将类别的路径指定为字符串，而不是实际的类，但是那不行。我也不能在派生类中指定一个字符串作为基类名。

I realize this is an issue of a circular dependency. Others have suggested of specifying the path to a class as a string instead of the actual class, but that does not work. I also cannot specify a string as the base class name in the derived class.

是否可以在没有重构我的模型的情况下执行循环依赖？

Is such a circular dependency possible without refactoring my models?

推荐答案

在 CommonFields 之间的某个地方导入 app1.models 和 SomeFields 。

Import app1.models somewhere between CommonFields and SomeFields.

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