本文介绍了为什么Django ManyToManyField导致管理界面崩溃？为什么没有通过表创建？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
为什么这行
users_favorited_by = models.ManyToManyField('auth.User')
或这个导致同样的错误：
or this one, which causes the same error:
users_favorited_by = models.ManyToManyField(User)
in this model
class Album(models.Model):
OFFICIALITY = (
('J', 'Major studio release'),
('I', 'Non-major official release'),
('U', 'Unofficial'),
)
title = models.CharField(max_length=70)
description = models.TextField(max_length=500, default="", null=True, blank=True)
pub_date = models.DateField('release date')
officiality = models.CharField(max_length=1, choices=OFFICIALITY)
is_concert = models.BooleanField(default=False)
main_info_url = models.URLField(blank=False)
thumbnail = models.FileField(upload_to=get_upload_file_name, blank=True, null=True)
#virtual field to skip over the through table.
songs = models.ManyToManyField("Song", through="AlbumSong")
users_favorited_by = models.ManyToManyField('auth.User')
#Alternative to Meta.ordering [2/2]:
#objects = AlbumAscPubDateManager()
def __str__(self):
return self.title
class Meta:
#Default ordering is by release date, ascending.
ordering = ['pub_date']
在管理界面导致此错误，点击某个专辑？
resulting in this error in the admin interface, when clicking on a specific album?
ProgrammingError at /admin/billyjoel/album/1/
relation "billyjoel_album_users_favorited_by" does not exist
LINE 1: ...LECT "auth_user"."id" FROM "auth_user" INNER JOIN "billyjoel...
^
管理界面工作正常，直到您点击相册查看其详细信息。
The admin interface works fine, until you click on an album to see its detail.
评论 ManyToManyField out，运行 makemigrations 然后迁移，并且管理界面工作正常 - 您可以看到相册的详细信息。
Comment that ManyToManyField out, run makemigrations then migrate, and the admin interface works fine--you can see the album's detail.
根据，错误意味着该列不存在在
According to this comment, the error implies that the column does not exist in the database.
那么为什么，当 - 注销 ManyToManyField （再次运行 makemigrations 然后 migrate ），没有创建数据库表？在我的中，前两个回覆者两者都声明应该自动创建通过表。那么它在哪里？
So why, when un-commenting out the ManyToManyField (and again running makemigrations then migrate), is no database table being created? As in my previous question, the first two answerers both state that an automatically-created through table should be made. So where is it?
jdb=# \dt public.*
List of relations
Schema | Name | Type | Owner
--------+----------------------------+-------+--------
public | auth_group | table | pguser
public | auth_group_permissions | table | pguser
public | auth_permission | table | pguser
public | auth_user | table | pguser
public | auth_user_groups | table | pguser
public | auth_user_user_permissions | table | pguser
public | billyjoel_album | table | pguser
public | billyjoel_albumsong | table | pguser
public | billyjoel_song | table | pguser
public | django_admin_log | table | pguser
public | django_content_type | table | pguser
public | django_migrations | table | pguser
public | django_session | table | pguser
(13 rows)
追溯：
Traceback:
Environment:
Request Method: GET
Request URL: http://127.0.0.1:8001/admin/billyjoel/album/1/
Django Version: 1.7c2
Python Version: 3.4.0
Installed Applications:
('django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'billyjoel')
Installed Middleware:
('django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware')
Traceback:
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/core/handlers/base.py" in get_response
111. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/contrib/admin/options.py" in wrapper
546. return self.admin_site.admin_view(view)(*args, **kwargs)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/utils/decorators.py" in _wrapped_view
105. response = view_func(request, *args, **kwargs)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/views/decorators/cache.py" in _wrapped_view_func
52. response = view_func(request, *args, **kwargs)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/contrib/admin/sites.py" in inner
204. return view(request, *args, **kwargs)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/contrib/admin/options.py" in change_view
1416. return self.changeform_view(request, object_id, form_url, extra_context)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/utils/decorators.py" in _wrapper
29. return bound_func(*args, **kwargs)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/utils/decorators.py" in _wrapped_view
105. response = view_func(request, *args, **kwargs)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/utils/decorators.py" in bound_func
25. return func.__get__(self, type(self))(*args2, **kwargs2)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/transaction.py" in inner
394. return func(*args, **kwargs)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/contrib/admin/options.py" in changeform_view
1378. form = ModelForm(instance=obj)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/forms/models.py" in __init__
319. object_data = model_to_dict(instance, opts.fields, opts.exclude)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/forms/models.py" in model_to_dict
149. data[f.name] = list(qs.values_list('pk', flat=True))
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/models/query.py" in __iter__
141. self._fetch_all()
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/models/query.py" in _fetch_all
964. self._result_cache = list(self.iterator())
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/models/query.py" in iterator
1200. for row in self.query.get_compiler(self.db).results_iter():
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/models/sql/compiler.py" in results_iter
699. for rows in self.execute_sql(MULTI):
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/models/sql/compiler.py" in execute_sql
785. cursor.execute(sql, params)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/backends/utils.py" in execute
81. return super(CursorDebugWrapper, self).execute(sql, params)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/backends/utils.py" in execute
65. return self.cursor.execute(sql, params)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/utils.py" in __exit__
94. six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/utils/six.py" in reraise
549. raise value.with_traceback(tb)
File "/home/jeffy/django_files/django_test_venv/lib/python3.4/site-packages/django/db/backends/utils.py" in execute
65. return self.cursor.execute(sql, params)
Exception Type: ProgrammingError at /admin/billyjoel/album/1/
Exception Value: relation "billyjoel_album_users_favorited_by" does not exist
LINE 1: ...LECT "auth_user"."id" FROM "auth_user" INNER JOIN "billyjoel...
^
推荐答案
我认为你的数据库处于不一致的状态门庭/迁移/取消注释。尝试完全删除数据库，删除迁移文件，并运行makemigrations并重新迁移。
I think your database is in an inconsistent state through all this commenting/migrating/uncommenting. Try dropping your db completely, deleting your migration files, and running makemigrations and migrate again.
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