我在Django中创建了一个自定义用户模型。我现在想用另一个名为Ambassadors的模型来扩展这个模型。
我得到的错误是“TransactionManagementError”。无论我尝试或阅读什么，我都找不到问题。你知道问题出在哪里吗？附上了Traceback以及models.py
Environment:
Request Method: POST
Request URL: http://127.0.0.1:8000/admin/accounts/myuser/add/
Django Version: 2.0.1
Python Version: 3.6.4
Installed Applications:
['django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'accounts']
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 "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
35. response = get_response(request)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
128. response = self.process_exception_by_middleware(e, request)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
126. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/admin/options.py" in wrapper
574. return self.admin_site.admin_view(view)(*args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in _wrapped_view
142. response = view_func(request, *args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/views/decorators/cache.py" in _wrapped_view_func
44. response = view_func(request, *args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/admin/sites.py" in inner
223. return view(request, *args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in _wrapper
62. return bound_func(*args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/views/decorators/debug.py" in sensitive_post_parameters_wrapper
76. return view(request, *args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in bound_func
58. return func.__get__(self, type(self))(*args2, **kwargs2)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in _wrapper
62. return bound_func(*args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in _wrapped_view
142. response = view_func(request, *args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in bound_func
58. return func.__get__(self, type(self))(*args2, **kwargs2)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/auth/admin.py" in add_view
100. return self._add_view(request, form_url, extra_context)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/auth/admin.py" in _add_view
127. return super().add_view(request, form_url, extra_context)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/admin/options.py" in add_view
1553. return self.changeform_view(request, None, form_url, extra_context)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in _wrapper
62. return bound_func(*args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in _wrapped_view
142. response = view_func(request, *args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/utils/decorators.py" in bound_func
58. return func.__get__(self, type(self))(*args2, **kwargs2)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/admin/options.py" in changeform_view
1450. return self._changeform_view(request, object_id, form_url, extra_context)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/admin/options.py" in _changeform_view
1494. self.log_addition(request, new_object, change_message)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/admin/options.py" in log_addition
773. change_message=message,
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/contrib/admin/models.py" in log_action
29. change_message=change_message,
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/manager.py" in manager_method
82. return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/query.py" in create
417. obj.save(force_insert=True, using=self.db)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/base.py" in save
729. force_update=force_update, update_fields=update_fields)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/base.py" in save_base
759. updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/base.py" in _save_table
842. result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/base.py" in _do_insert
880. using=using, raw=raw)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/manager.py" in manager_method
82. return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/query.py" in _insert
1125. return query.get_compiler(using=using).execute_sql(return_id)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/models/sql/compiler.py" in execute_sql
1281. cursor.execute(sql, params)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/backends/utils.py" in execute
100. return super().execute(sql, params)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/backends/utils.py" in execute
68. return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/backends/utils.py" in _execute_with_wrappers
77. return executor(sql, params, many, context)
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/backends/utils.py" in _execute
80. self.db.validate_no_broken_transaction()
File "/Users/Marc/Desktop/Dev/accounts/lib/python3.6/site-packages/django/db/backends/base/base.py" in validate_no_broken_transaction
437. "An error occurred in the current transaction. You can't "
Exception Type: TransactionManagementError at /admin/accounts/myuser/add/
Exception Value: An error occurred in the current transaction. You can't execute queries until the end of the 'atomic' block.
models.py
from django.conf import settings
from django.contrib.auth.models import (
BaseUserManager, AbstractBaseUser
)
from django.db import models
from django.db.models.signals import post_save
# Create your models here.
class MyUserManager(BaseUserManager):
def create_user(self, email, password=None):
"""
Creates and saves a User with the given email, date of
birth and password.
"""
if not email:
raise ValueError('Users must have an email address')
user = self.model(
email=self.normalize_email(email),
)
user.set_password(password)
user.save(using=self._db)
return user
def create_superuser(self, email, password):
"""
Creates and saves a superuser with the given email, date of
birth and password.
"""
user = self.create_user(
email,
password=password,
)
user.is_admin = True
user.save(using=self._db)
return user
class MyUser(AbstractBaseUser):
email = models.EmailField(
verbose_name='email address',
max_length=255,
unique=True,
)
is_active = models.BooleanField(default=True)
is_admin = models.BooleanField(default=False)
objects = MyUserManager()
USERNAME_FIELD = 'email'
#REQUIRED_FIELDS = ['']
def __str__(self):
return self.email
def has_perm(self, perm, obj=None):
"Does the user have a specific permission?"
# Simplest possible answer: Yes, always
return True
def has_module_perms(self, app_label):
"Does the user have permissions to view the app `app_label`?"
# Simplest possible answer: Yes, always
return True
@property
def is_staff(self):
"Is the user a member of staff?"
# Simplest possible answer: All admins are staff
return self.is_admin
class Ambassador(models.Model):
user = models.ForeignKey(
settings.AUTH_USER_MODEL,
on_delete=models.CASCADE,
)
coupon_id = models.IntegerField()
coupon_code = models.CharField(max_length=30)
def __str__(self):
return str(self.user.email)
def post_save_receiver(sender, instance, created, **kwargs):
if created:
try:
Ambassador.objects.create(user=instance)
except:
pass
post_save.connect(post_save_receiver, sender=settings.AUTH_USER_MODEL)
答案 0 :(得分：0)
所以我在寻找解决方案方面迈出了一大步。将coupon_id = models.IntegerField()更改为coupon_id = models.IntegerField(blank=True, null=True)后，它突然变得有效了。我不明白100％的原因，但也许这里有人可以向我解释一下吗？
答案 1 :(得分：0)
你有一个创建大使的保存后信号。
def post_save_receiver(sender, instance, created, **kwargs):
if created:
try:
Ambassador.objects.create(user=instance)
except:
pass
但是，您尚未指定coupon_id并且它已null=False，因此提出了IntegrityError。由于异常没有被原子块捕获，因此你得到了模糊的TransactionManagementError。
您可以在创建对象时指定coupon_id，向字段添加默认值或将字段更改为null=True来解决问题。
一个关键的教训是，执行try: except来捕获所有异常通常是一个坏主意。在这种情况下，代码永远不会起作用，但是因为你执行了pass代码并且你可能没有发现它，除非它导致了第二个错误。