为什么我不能在 django 中导入用户模型？

Question

I am building a django web app with a custom user model which extends the AbstractBaseUser. In one of my models I need to use this custom user model:

from accounts.models import User

class History(models.Model):
    user = models.ForeignKey(User)
    job = models.ForeignKey(Job)

When I try to run the python manage.py makemigrations command this error message is outputted:

ImportError: cannot import name User

In my settings.py I do the following to let django know that there is a custom user model:

AUTH_USER_MODEL = "accounts.User"

I am puzzled as to what I am doing wrong. Surely there must be a way to import this model that I do not know of. How do I fix this?

I have tried to use the get_user_model() method, however it doesn't work in the model as the models haven't loaded yet. This is therefore not a solution. Any other ideas?

Thank you in advance.

Answer 1

You can do as follows:

from django.conf import settings
class History(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL)
    job = models.ForeignKey(Job)

Please refer to documentation for more details.

如果您直接引用 User（例如，通过在外键中引用它），您的代码将无法在 AUTH_USER_MODEL 设置已更改为不同用户模型的项目中工作。

get_user_model()[来源]

您应该使用 django.contrib.auth.get_user_model() 来引用用户模型，而不是直接引用 User。此方法将返回当前活动的用户模型 - 如果指定了自定义用户模型，否则为 User。

当您为用户模型定义外键或多对多关系时，您应该使用 AUTH_USER_MODEL 设置指定自定义模型。例如