重寫用戶模型時報錯AttributeError: type object ‘自定義類’ has no attribute ‘USERNAME_FIELD’

view中導入:from django.contrib.auth.models import AbstractBaseUser

settings.py中設置了：AUTH_USER_MODEL='app名.model自定義類'

解決方法:在自定義類中加：

　　identifier = models.CharField(max_length=40, unique=True)
　　USERNAME_FIELD = 'identifier'

view中導入from django.contrib.auth.models import AbstractUser 則不會出現該問題