如何解决Django中的错误“ / admin / auth / user / add / UNIQUE约束失败的IntegrityError：user_details_profile.phone”？

Question

我正在尝试通过内置的django管理员添加新用户，但我一直收到此错误。即使尝试通过终端创建超级用户也会遇到相同的错误。与用户无关的所有其他模型都可以正常工作。我的models.py文件中的代码如下。

from django.db import models
from django.db.models.signals import post_save
from django.contrib.auth.models import User
from django.dispatch import receiver
from django.core.exceptions import ObjectDoesNotExist
from general.models import Ward

# Create your models here.
class Profile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    firstname = models.CharField(max_length=20)
    middlename = models.CharField(max_length=20)
    lastname = models.CharField(max_length=20)
    loc_id = models.CharField(max_length=8, unique=True)
    ward = models.ForeignKey(Ward, related_name="wards", null=True, on_delete=models.SET_NULL)
    phone = models.CharField(max_length=10, unique=True)
    address = models.CharField(max_length=255)
    postal_code = models.CharField(max_length=15)

    def __str__(self):
        return "{} {}".format(self.user.first_name, self.user.last_name)

    class Meta:
        verbose_name_plural = "Personal information"

@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
    try:
        instance.profile.save()
    except ObjectDoesNotExist:
        Profile.objects.create(user=instance)

@receiver(post_save, sender=User)
def save_user_profile(sender, instance, **kwargs):
    try:
        instance.profile.save()
    except ObjectDoesNotExist:
        Profile.objects.create(user=instance)

错误回溯：

Environment:
Request Method: POST
Request URL: http://localhost:8000/admin/auth/user/add/

Django Version: 2.1.1
Python Version: 3.6.0
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'rest_framework',
 'general',
 'user_details']
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:\xampp\htdocs\python\projects\tanariver\user_details\models.py" in create_user_profile
  30.         instance.profile.save()

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
  414.                     self.related.get_accessor_name()

During handling of the above exception (User has no profile.), another exception occurred:

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\backends\utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\backends\sqlite3\base.py" in execute
  296.         return Database.Cursor.execute(self, query, params)

The above exception (UNIQUE constraint failed: user_details_profile.phone) was the direct cause of the following exception:

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\core\handlers\exception.py" in inner
  34.             response = get_response(request)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\core\handlers\base.py" in _get_response
  126.                 response = self.process_exception_by_middleware(e, request)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\core\handlers\base.py" in _get_response
  124.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\admin\options.py" in wrapper
  604.                 return self.admin_site.admin_view(view)(*args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\views\decorators\cache.py" in _wrapped_view_func
  44.         response = view_func(request, *args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\admin\sites.py" in inner
  223.             return view(request, *args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\utils\decorators.py" in _wrapper
  45.         return bound_method(*args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\views\decorators\debug.py" in sensitive_post_parameters_wrapper
  76.             return view(request, *args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\utils\decorators.py" in _wrapper
  45.         return bound_method(*args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\auth\admin.py" in add_view
  98.             return self._add_view(request, form_url, extra_context)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\auth\admin.py" in _add_view
  125.         return super().add_view(request, form_url, extra_context)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\admin\options.py" in add_view
  1636.         return self.changeform_view(request, None, form_url, extra_context)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\utils\decorators.py" in _wrapper
  45.         return bound_method(*args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\admin\options.py" in changeform_view
  1525.             return self._changeform_view(request, object_id, form_url, extra_context)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\admin\options.py" in _changeform_view
  1564.                 self.save_model(request, new_object, form, not add)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\admin\options.py" in save_model
  1091.         obj.save()

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\contrib\auth\base_user.py" in save
  73.         super().save(*args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\base.py" in save
  718.                        force_update=force_update, update_fields=update_fields)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\base.py" in save_base
  758.                 update_fields=update_fields, raw=raw, using=using,

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\dispatch\dispatcher.py" in send
  175.             for receiver in self._live_receivers(sender)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\dispatch\dispatcher.py" in <listcomp>
  175.             for receiver in self._live_receivers(sender)

File "C:\xampp\htdocs\python\projects\tanariver\user_details\models.py" in create_user_profile
  32.         Profile.objects.create(user=instance)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\manager.py" in manager_method
  82.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\query.py" in create
  413.         obj.save(force_insert=True, using=self.db)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\base.py" in save
  718.                        force_update=force_update, update_fields=update_fields)

File "C:\xampp\htdocs\python\envs\tanariver\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:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\base.py" in _save_table
  831.             result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\base.py" in _do_insert
  869.                                using=using, raw=raw)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\manager.py" in manager_method
  82.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\query.py" in _insert
  1136.         return query.get_compiler(using=using).execute_sql(return_id)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\models\sql\compiler.py" in execute_sql
  1289.                 cursor.execute(sql, params)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\backends\utils.py" in execute
  100.             return super().execute(sql, params)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\backends\utils.py" in execute
  68.         return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\backends\utils.py" in _execute_with_wrappers
  77.         return executor(sql, params, many, context)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\backends\utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\utils.py" in __exit__
  89.                 raise dj_exc_value.with_traceback(traceback) from exc_value

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\backends\utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

File "C:\xampp\htdocs\python\envs\tanariver\lib\site-packages\django\db\backends\sqlite3\base.py" in execute
  296.         return Database.Cursor.execute(self, query, params)

Exception Type: IntegrityError at /admin/auth/user/add/
Exception Value: UNIQUE constraint failed: user_details_profile.phone

我想念什么？

Answer 1

您似乎遇到的错误与您声明为unique=True的电话号码字段有关。您是否要添加用户并为该用户提供与数据库中已有用户相同的电话号码？

Answer 2

@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
    try:
        instance.profile.save()
    except ObjectDoesNotExist:
        Profile.objects.create(user=instance)

考虑一下：每次在数据库上创建并保存一个User条目时，此代码都会在数据库上创建并保存一个Profile条目并链接到它。现在，您提供的用于创建配置文件条目的唯一信息是与之相关的用户对象。

创建第一个用户时，相应的配置文件条目仅填充user字段，其他所有字段均为空白/空值-甚至phone。如果您将其保留不变，然后创建另一个用户，那么它的配置文件也将使用空字符串phone来创建；那么您的唯一约束失败。

可能的解决方案：在这种情况下避免使用必填字段，在适当的地方为非null字段提供有意义的默认值，在创建对象期间为唯一字段传递唯一值，进行验证！，预见并捕获异常只要有意义，在编写创建条目的方法时都要遵守模型约束...

@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
    try:
        instance.profile.save()
    except ObjectDoesNotExist:
        phone = meaningful_phone_defaut_or_passed_argument
        # (...) other defaults
        Profile.objects.create(user=instance, phone=phone, )