PythonDjango-将外键与用户关联。IntegrityError非空约束失败

我正在用Django创建一个网站（显然），我在创建用户时遇到了一个问题。我想将我的用户与一个称为类的模型相关联，该类包含多个用户。我假设我需要使用

models.OneToOneField（）

将一个类与多个用户关联起来。但是，例如，当我在终端中创建一个超级用户时，当我键入最后一位所需信息并按下enter键时，我会立即得到一个

IntegrityError

。基本上，我只希望一个名为

类的模型

有多个用户与之关联，每个类都有不同的

密钥

/authentication（如

models.py

所示），以便在我的网站上执行不同的操作

完全回溯（尝试创建超级用户后）：

project/users/admin.py

：

from django.contrib.auth.models import AbstractUser, BaseUserManager
from django.db import models
from django.utils.translation import ugettext_lazy as _


class UserManager(BaseUserManager):
    """Define a model manager for User model with no username field."""

    use_in_migrations = True

    def _create_user(self, email, password, **extra_fields):
        """Create and save a User with the given email and password."""
        if not email:
            raise ValueError('The given email must be set')
        email = self.normalize_email(email)
        user = self.model(email=email, **extra_fields)
        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_user(self, email, password=None, **extra_fields):
        """Create and save a regular User with the given email and password."""
        extra_fields.setdefault('is_staff', False)
        extra_fields.setdefault('is_superuser', False)
        return self._create_user(email, password, **extra_fields)

    def create_superuser(self, email, password, **extra_fields):
        """Create and save a SuperUser with the given email and password."""
        extra_fields.setdefault('is_staff', True)
        extra_fields.setdefault('is_superuser', True)

        if extra_fields.get('is_staff') is not True:
            raise ValueError('Superuser must have is_staff=True.')
        if extra_fields.get('is_superuser') is not True:
            raise ValueError('Superuser must have is_superuser=True.')

        return self._create_user(email, password, **extra_fields)


class Keys(models.Model):
    """A Model to represent any kind of auth key."""
    key = models.CharField(max_length=250, blank=False, default="")

    kind_of_authorisation = models.CharField(max_length=100, blank=False, default="")

    class Meta:
        verbose_name_plural = "Keys"


class Class(models.Model):
    """A model to represent all kinds of classes."""
    name = models.CharField(max_length=100, blank=False, default="", unique=True)
    class_id = models.CharField(max_length=200, blank=False, default="", unique=True)

    authorisations = models.ForeignKey(Keys, on_delete=models.CASCADE, blank=False)

    class Meta:
        verbose_name_plural = "Classes"


class User(AbstractUser):
    """User model."""
    username = models.CharField(max_length=75, unique=True)
    email = models.EmailField(_('email address'), unique=True)
    first_name = models.CharField(max_length=100, blank=False, default="")
    last_name = models.CharField(max_length=100, blank=False, default="")

    # It's this field that I don't know about.
    parent_class = models.ForeignKey(Class, on_delete=models.CASCADE,
                                     null=True)

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['username', 'first_name', 'last_name']

    objects = UserManager()

from django.contrib import admin
from django.contrib.auth.admin import UserAdmin as DjangoUserAdmin
from django.utils.translation import ugettext_lazy as _

from .models import User, Class, Keys


@admin.register(User)
class UserAdmin(DjangoUserAdmin):
    """Define admin model for custom User model with no email field."""

    fieldsets = (
        (None, {'fields': ('email', 'password')}),
        (_('Personal info'), {'fields': ('first_name', 'last_name')}),
        (_('Permissions'), {'fields': ('is_active', 'is_staff', 'is_superuser',
                                       'groups', 'user_permissions')}),
        (_('Important dates'), {'fields': ('last_login', 'date_joined')}),
    )
    add_fieldsets = (
        (None, {
            'classes': ('wide',),
            'fields': ('email', 'password1', 'password2'),
        }),
    )
    list_display = ('email', 'first_name', 'last_name', 'is_staff')
    search_fields = ('email', 'first_name', 'last_name')
    ordering = ('email',)


admin.site.register(Class)
admin.site.register(Keys)

from django import forms
from django.contrib.auth.forms import UserCreationForm, UserChangeForm

from .models import User, Class, Keys
from explore_database import functions as func


class CreateUserForm(UserCreationForm):
    # Require the email field.
    email = forms.EmailField(required=True)

    class Meta:
        model = User
        fields = ("email", "username", "password1",
                  "password2")

    def save(self, commit=True):
        user = super(UserCreationForm, self).save(commit=False)
        # Get all the relevant data, and save it.
        user.email = self.cleaned_data["email"]
        user.username = self.cleaned_data["username"]

        # Save the newly created user.
        if commit:
            user.save()
        return user


class EditProfileForm(UserChangeForm):
    password = None

    class Meta:
        model = User
        fields = ("email", "username")


class CreateClass(forms.ModelForm):

    class Meta:
        model = Class
        fields = ("name", "class_id", "authorisations")


class CreateKey(forms.ModelForm):

    class Meta:
        model = Keys
        fields = ("key", "kind_of_authorisation")

project/users/forms.py

：

from django.contrib.auth.models import AbstractUser, BaseUserManager
from django.db import models
from django.utils.translation import ugettext_lazy as _


class UserManager(BaseUserManager):
    """Define a model manager for User model with no username field."""

    use_in_migrations = True

    def _create_user(self, email, password, **extra_fields):
        """Create and save a User with the given email and password."""
        if not email:
            raise ValueError('The given email must be set')
        email = self.normalize_email(email)
        user = self.model(email=email, **extra_fields)
        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_user(self, email, password=None, **extra_fields):
        """Create and save a regular User with the given email and password."""
        extra_fields.setdefault('is_staff', False)
        extra_fields.setdefault('is_superuser', False)
        return self._create_user(email, password, **extra_fields)

    def create_superuser(self, email, password, **extra_fields):
        """Create and save a SuperUser with the given email and password."""
        extra_fields.setdefault('is_staff', True)
        extra_fields.setdefault('is_superuser', True)

        if extra_fields.get('is_staff') is not True:
            raise ValueError('Superuser must have is_staff=True.')
        if extra_fields.get('is_superuser') is not True:
            raise ValueError('Superuser must have is_superuser=True.')

        return self._create_user(email, password, **extra_fields)


class Keys(models.Model):
    """A Model to represent any kind of auth key."""
    key = models.CharField(max_length=250, blank=False, default="")

    kind_of_authorisation = models.CharField(max_length=100, blank=False, default="")

    class Meta:
        verbose_name_plural = "Keys"


class Class(models.Model):
    """A model to represent all kinds of classes."""
    name = models.CharField(max_length=100, blank=False, default="", unique=True)
    class_id = models.CharField(max_length=200, blank=False, default="", unique=True)

    authorisations = models.ForeignKey(Keys, on_delete=models.CASCADE, blank=False)

    class Meta:
        verbose_name_plural = "Classes"


class User(AbstractUser):
    """User model."""
    username = models.CharField(max_length=75, unique=True)
    email = models.EmailField(_('email address'), unique=True)
    first_name = models.CharField(max_length=100, blank=False, default="")
    last_name = models.CharField(max_length=100, blank=False, default="")

    # It's this field that I don't know about.
    parent_class = models.ForeignKey(Class, on_delete=models.CASCADE,
                                     null=True)

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['username', 'first_name', 'last_name']

    objects = UserManager()

from django.contrib import admin
from django.contrib.auth.admin import UserAdmin as DjangoUserAdmin
from django.utils.translation import ugettext_lazy as _

from .models import User, Class, Keys


@admin.register(User)
class UserAdmin(DjangoUserAdmin):
    """Define admin model for custom User model with no email field."""

    fieldsets = (
        (None, {'fields': ('email', 'password')}),
        (_('Personal info'), {'fields': ('first_name', 'last_name')}),
        (_('Permissions'), {'fields': ('is_active', 'is_staff', 'is_superuser',
                                       'groups', 'user_permissions')}),
        (_('Important dates'), {'fields': ('last_login', 'date_joined')}),
    )
    add_fieldsets = (
        (None, {
            'classes': ('wide',),
            'fields': ('email', 'password1', 'password2'),
        }),
    )
    list_display = ('email', 'first_name', 'last_name', 'is_staff')
    search_fields = ('email', 'first_name', 'last_name')
    ordering = ('email',)


admin.site.register(Class)
admin.site.register(Keys)

from django import forms
from django.contrib.auth.forms import UserCreationForm, UserChangeForm

from .models import User, Class, Keys
from explore_database import functions as func


class CreateUserForm(UserCreationForm):
    # Require the email field.
    email = forms.EmailField(required=True)

    class Meta:
        model = User
        fields = ("email", "username", "password1",
                  "password2")

    def save(self, commit=True):
        user = super(UserCreationForm, self).save(commit=False)
        # Get all the relevant data, and save it.
        user.email = self.cleaned_data["email"]
        user.username = self.cleaned_data["username"]

        # Save the newly created user.
        if commit:
            user.save()
        return user


class EditProfileForm(UserChangeForm):
    password = None

    class Meta:
        model = User
        fields = ("email", "username")


class CreateClass(forms.ModelForm):

    class Meta:
        model = Class
        fields = ("name", "class_id", "authorisations")


class CreateKey(forms.ModelForm):

    class Meta:
        model = Keys
        fields = ("key", "kind_of_authorisation")

非常感谢您的帮助。谢谢

更新： 好吧，我有一个超级用户。我设置了

null=True

，并成功创建了超级用户。但是，现在我看不出应该在admin中为超级用户设置类的位置。我可以将类实例与超级用户关联的唯一方法是，进入

python manage.py shell

，然后手动将我在admin中创建的类实例添加到超级用户

django.db.utils.IntegrityError: NOT NULL constraint failed: users_user.parent_class_id

已将一个或多个用户对象保存到数据库中。通过添加此OneToOneField，这些现有记录的值将为Null，这意味着它们当前没有指向父类对象

你有两个选择：

One:编辑Django模型，使Null为可接受值

parent\u class=models.OneToOneField（class，on\u delete=models.CASCADE，null=True）

Two:创建一个新的迁移，在其中为Django提供此字段的默认值（例如无）

已将一个或多个用户对象保存到数据库中。通过添加此OneToOneField，这些现有记录的值将为Null，这意味着它们当前没有指向父类对象

你有两个选择：

One:编辑Django模型，使Null为可接受值

parent\u class=models.OneToOneField（class，on\u delete=models.CASCADE，null=True）

---

Two:创建一个新的迁移，在其中为Django提供此字段的默认值（例如无）

为什么要使用OneToOneFIeld“将一个类与多个用户关联”？顾名思义，该字段仅将一个类与一个用户关联。但在任何情况下，都会发生该错误，因为您创建的用户未关联任何类。我不明白你怎么说

null=True

；如果你想让这个类的能力为空，那么这就是你所需要的。@DanielRoseman如果我不够清楚，很抱歉。那么，我应该使用

models.ForeignKey（）

吗？因为我也试过了，它给了我同样的错误。你认为呢？是的，但正如我所说的，你需要在创建用户时实际设置父类，或者让字段null=True。这两个都可以解决问题。@DanielRoseman好的。但是在创建超级用户之前，我如何创建一个类呢？你能在python manage.py shell中实现吗？为什么要使用OneToOneFIeld来“将一个类与多个用户关联”？顾名思义，该字段仅将一个类与一个用户关联。但在任何情况下，都会发生该错误，因为您创建的用户未关联任何类。我不明白你怎么说

null=True

；如果你想让这个类的能力为空，那么这就是你所需要的。@DanielRoseman如果我不够清楚，很抱歉。那么，我应该使用

models.ForeignKey（）

吗？因为我也试过了，它给了我同样的错误。你认为呢？是的，但正如我所说的，你需要在创建用户时实际设置父类，或者让字段null=True。这两个都可以解决问题。@DanielRoseman好的。但是在创建超级用户之前，我如何创建一个类呢？你能在python manage.py shell中完成吗？这不是关于迁移的问题。这不是关于迁移的问题。