管理员中的 Django 自定义用户模型，关系 "auth_user"不存在

Question

我有一个自定义用户模型，如下所示:

class User(AbstractUser):
    subscribe_newsletters = models.BooleanField(default=True)
    old_id = models.IntegerField(null=True, blank=True)
    old_source = models.CharField(max_length=25, null=True, blank=True)

并使用内置的 UserAdmin

admin.site.register(User, UserAdmin)

虽然编辑用户记录工作正常，但是当我添加用户时，出现以下错误

Exception Value: 
relation "auth_user" does not exist
LINE 1: ...user"."is_active", "auth_user"."date_joined" FROM "auth_user...

Answer 1

经过一番挖掘，我发现了这个

https://docs.djangoproject.com/en/1.5/topics/auth/customizing/#custom-users-and-the-built-in-auth-forms

罪魁祸首是函数clean_username内UserCreationForm内django.contrib.auth.forms.py .已经创建了一些票证，但显然维护者并不认为这是一个缺陷:

https://code.djangoproject.com/ticket/20188

https://code.djangoproject.com/ticket/20086

def clean_username(self):
        # Since User.username is unique, this check is redundant,
        # but it sets a nicer error message than the ORM. See #13147.
        username = self.cleaned_data["username"]
        try:
            User._default_manager.get(username=username)
        except User.DoesNotExist:
            return username
        raise forms.ValidationError(self.error_messages['duplicate_username'])

User在此文件中直接引用内置用户模型。

为了解决这个问题，我创建了我的自定义表单

from models import User #you can use get_user_model
from django.contrib.auth.forms import UserCreationForm
from django.contrib.auth.admin import UserAdmin
from django.contrib.auth import forms

class MyUserCreationForm(UserCreationForm):
    def clean_username(self):
        # Since User.username is unique, this check is redundant,
        # but it sets a nicer error message than the ORM. See #13147.
        username = self.cleaned_data["username"]
        try:
            User._default_manager.get(username=username)
        except User.DoesNotExist:
            return username
        raise forms.ValidationError(self.error_messages['duplicate_username'])

    class Meta(UserCreationForm.Meta):
        model = User

class MyUserAdmin(UserAdmin):  
    add_form = MyUserCreationForm   

admin.site.register(User,MyUserAdmin)

或者您可以尝试猴子修补原始 UserCreationForm替换 User多变的。