如何在 Django 中控制对象是否与模型相关？

Question

有几个与用户模型相关的模型：

class User(AbstractUser):
  # Its fields

class Model_1(models.Model)
  user = models.OneToOneField('User', on_delete=models.CASCADE)
  # other fields

class Model_2(models.Model)
  user = models.OneToOneField('User', on_delete=models.CASCADE)
  # other fields

class Model_3(models.Model)
  user = models.OneToOneField('User', on_delete=models.CASCADE)
  # other fields

class Model_4(models.Model)
  user = models.OneToOneField('User', on_delete=models.CASCADE)
  # other fields

在视图中：

def index(request):
    # If the user is related to model one, do something
    # If the user is related to model two, do something
    # If the user is related to model three, do something
    # If the user is related to model four, do something
    # Otherwise return to the home page

---

用户向View发送请求后，如何判断它属于这些模型中的哪一个？
提前谢谢你。

Answer 1

只需检查您的模型在用户实例中是否存在

class Model_4(models.Model)
  user = models.OneToOneField('User',
                              related_name='model_4',
                              on_delete=models.CASCADE)

def index(request):
    if request.user.model_4 is not None:
        pass  # Do something