How to resolve IntegrityError which caused Foreign Key constraint failed

Question

I encountered this error when trying to update/add/delete users in the Admin.

I don't really know what is referencing my model, that has caused the Foreign key constraint to fail.

Below is the model.py, forms.py, and admin.py

Error

IntegrityError at /admin/signup/user/

FOREIGN KEY constraint failed

Request Method:     POST
Request URL:    http://127.0.0.1:8000/admin/signup/user/
Django Version:     2.1.4
Exception Type:     IntegrityError
Exception Value:    

FOREIGN KEY constraint failed

Exception Location:     C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\backends\base\base.py in _commit, line 239
Python Executable:  C:\Users\MY PC\AppData\Local\Programs\Python\Python36\python.exe
Python Version:     3.6.5
Python Path:    

['C:\\Users\\MY PC\\Documents\\Github\\Calendaring App\\meetme',
 'C:\\Users\\MY PC\\AppData\\Local\\Programs\\Python\\Python36\\python36.zip',
 'C:\\Users\\MY PC\\AppData\\Local\\Programs\\Python\\Python36\\DLLs',
 'C:\\Users\\MY PC\\AppData\\Local\\Programs\\Python\\Python36\\lib',
 'C:\\Users\\MY PC\\AppData\\Local\\Programs\\Python\\Python36',
 'C:\\Users\\MY PC\\AppData\\Roaming\\Python\\Python36\\site-packages',
 'C:\\Users\\MY '
 'PC\\AppData\\Local\\Programs\\Python\\Python36\\lib\\site-packages']

Traceback:

Environment:


Request Method: POST
Request URL: http://127.0.0.1:8000/admin/signup/user/

Django Version: 2.1.4
Python Version: 3.6.5
Installed Applications:
['login.apps.LoginConfig',
 'signup.apps.SignupConfig',
 'homepage.apps.HomepageConfig',
 'main.apps.MainConfig',
 'crispy_forms',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback:

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\backends\base\base.py" in _commit
239. return self.connection.commit()


The above exception (FOREIGN KEY constraint failed) was the direct cause of the following exception:

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\core\handlers\exception.py" in inner
  34.             response = get_response(request)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\core\handlers\base.py" in _get_response
  126.                 response = self.process_exception_by_middleware(e, request)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\core\handlers\base.py" in _get_response
  124.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\options.py" in wrapper
  604.                 return self.admin_site.admin_view(view)(*args, **kwargs)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\views\decorators\cache.py" in _wrapped_view_func
  44.         response = view_func(request, *args, **kwargs)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\sites.py" in inner
  223.             return view(request, *args, **kwargs)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\utils\decorators.py" in _wrapper
  45.         return bound_method(*args, **kwargs)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\options.py" in changelist_view
  1717.                 response = self.response_action(request, queryset=cl.get_queryset(request))

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\options.py" in response_action
  1400.             response = func(self, request, queryset)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\actions.py" in delete_selected
  39.                 modeladmin.log_deletion(request, obj, obj_display)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\options.py" in log_deletion
  842.             action_flag=DELETION,

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\models.py" in log_action
  35.             change_message=change_message,

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\models\manager.py" in manager_method
  82.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\models\query.py" in create
  413.         obj.save(force_insert=True, using=self.db)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\models\base.py" in save
  718.                        force_update=force_update, update_fields=update_fields)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\models\base.py" in save_base
  748.             updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\transaction.py" in __exit__
  212.                         connection.commit()

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\backends\base\base.py" in commit
  261.         self._commit()

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\backends\base\base.py" in _commit
  239.                 return self.connection.commit()

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\utils.py" in __exit__
  89.                 raise dj_exc_value.with_traceback(traceback) from exc_value

File "C:\Users\MY PC\AppData\Local\Programs\Python\Python36\lib\site-packages\django\db\backends\base\base.py" in _commit
239. return self.connection.commit()

Exception Type: IntegrityError at /admin/signup/user/
Exception Value: FOREIGN KEY constraint failed

Model.py

This is my custom user model for the Signup.

class UserManager(BaseUserManager):
    use_in_migrations = True

    def _create_user(self, email, password, **extra_fields):
        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):
        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):
        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 User(AbstractUser):
    first_name = models.CharField(max_length=35, blank=False, null=False)
    last_name = models.CharField(max_length=35, blank=False, null=False)

    username = None
    email = models.EmailField(_('email address'), unique=True)

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = []

    objects = UserManager()

forms.py

Also, my form is defined as this

class SignUpForm(UserCreationForm):

    class Meta:
        model = User
        fields = ('first_name', 'last_name', 'email',)


    def __init__(self, *args, **kwargs):
        super(UserCreationForm, self).__init__(*args, **kwargs) 

        helper = self.helper = FormHelper()
        layout = helper.layout = Layout()
        for field_name, field in self.fields.items():
            layout.append(Field(field_name, placeholder=field.label))
        helper.form_show_labels = False

        super(UserCreationForm, self).__init__(*args, **kwargs)
        self.fields['password1'].help_text = ""
        self.fields['password2'].help_text = ""

        for field_name in self.fields:
            field = self.fields.get(field_name)
            if field:
                if type(field.widget) in (forms.CharField, forms.EmailField):
                    field.widget = forms.CharField(attrs = {'placeholder': field.label})

class SignUpFormChangeForm(UserChangeForm):

    class Meta:
        model = User
        fields = ('first_name', 'last_name', 'email',)

Admin.py

class MyUserAdmin(UserAdmin):
    model = User
    add_form = SignUpForm
    form = SignUpFormChangeForm
    list_display = ('email', 'first_name', 'last_name', 'is_staff')
    search_fields = ('email', 'first_name', 'last_name')
    ordering = ('email',)

admin.site.register(User, MyUserAdmin)

settings.py

AUTH_USER_MODEL = 'signup.User'

Also, your if statement inside your form init is nonsense and will never execute. Widgets are not fields. — Daniel Roseman, Feb 05 '19 at 10:50
I'm new to Django. Yes, thank you. I also noticed it doesn't execute. That's one of the challenges I'm facing. I want to set a placeholder for Crispy form. — OLADIPUPO RIDWAN OLAYINKA, Feb 05 '19 at 11:24
There's still not enough information here. Is DEBUG set to True? There are no foreign keys defined in your user model so it's impossible to tell what is causing the integrity error. — Daniel Roseman, Feb 05 '19 at 11:35
I have been wondering too, I don't know where this is coming from — OLADIPUPO RIDWAN OLAYINKA, Feb 05 '19 at 11:59
Have you been able to fix this? Experiencing the same problem — Peter, Oct 23 '19 at 12:00

score 0 · Answer 1 · answered Jul 11 '20 at 07:59

I figured this has to be because we have an actual table already in db which is not linked to other table, which may cause this error.

delete all migrations from main folder(just leave init.py) and deleted the db.sqllite3 file.

Ran make migrations and migrate again and this time it worked.

Need to create tables again and make sure that they are linked to a each other or else it will fail during save.

How to resolve IntegrityError which caused Foreign Key constraint failed

1 Answers1