在 django 中进行迁移错误：“没有这样的表”答案

【问题标题】：Make migrations error in django: "no such table"在 django 中进行迁移错误：“没有这样的表”
【发布时间】：2020-04-15 16:18:48
【问题描述】：

当我尝试进行迁移时：python manage.py makemigrations

出现以下错误：django.db.utils.OperationalError: no such table: blog_category

Traceback (most recent call last):
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django \db\backends\sqlite3\base.py", line 383, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such table: blog_category

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "manage.py", line 15, in <module>
execute_from_command_line(sys.argv)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django \core\management\__init__.py", line 381, in execute_from_command_line
utility.execute()
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\management\__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\management\base.py", line 323, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\management\base.py", line 361, in execute
self.check()
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\management\base.py", line 390, in check
include_deployment_checks=include_deployment_checks,
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\management\base.py", line 377, in _run_checks
return checks.run_checks(**kwargs)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\checks\registry.py", line 72, in run_checks
new_errors = check(app_configs=app_configs)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\checks\urls.py", line 40, in check_url_namespaces_unique
all_namespaces = _load_all_namespaces(resolver)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\checks\urls.py", line 57, in _load_all_namespaces
url_patterns = getattr(resolver, 'url_patterns', [])
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\utils\functional.py", line 80, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\urls\resolvers.py", line 571, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\utils\functional.py", line 80, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\urls\resolvers.py", line 564, in urlconf_module
return import_module(self.urlconf_name)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\importlib\__init__.py",   line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
File "<frozen importlib._bootstrap>", line 983, in _find_and_load
File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "C:\xampp\htdocs\Django project\blooper\Bona-Blog-master\bona_blog\urls.py", line 27, in <module>
path('', include('blog.urls', namespace='blog')),  # Urls for article app.
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\urls\conf.py", line 34, in include
urlconf_module = import_module(urlconf_module)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\importlib\__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
File "<frozen importlib._bootstrap>", line 983, in _find_and_load
File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "C:\xampp\htdocs\Django project\blooper\Bona-Blog-master\blog\urls.py", line 5, in <module>
from blog.views.blog.article_views import (
File "C:\xampp\htdocs\Django project\blooper\Bona-Blog-master\blog\views\blog\article_views.py", line 25, in <module>
from blog.forms.blog.article_forms import (
File "C:\xampp\htdocs\Django project\blooper\Bona-Blog-master\blog\forms\blog\article_forms.py", line 16, in <module>
class ArticleCreateForm(forms.ModelForm):
File "C:\xampp\htdocs\Django project\blooper\Bona-Blog-master\blog\forms\blog\article_forms.py", line 18, in ArticleCreateForm
class Meta:
File "C:\xampp\htdocs\Django project\blooper\Bona-Blog-master\blog\forms\blog\article_forms.py", line 47, in Meta
"data-live-search": "true"
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\forms\widgets.py", line 562, in __init__
self.choices = list(choices)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\models\query.py", line 274, in __iter__
self._fetch_all()
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\models\query.py", line 1242, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\models\query.py", line 55, in __iter__
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\models\sql\compiler.py", line 1097, in execute_sql
cursor.execute(sql, params)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\backends\utils.py", line 99, in execute
return super().execute(sql, params)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\backends\utils.py", line 67, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\backends\utils.py", line 76, in _execute_with_wrappers
return executor(sql, params, many, context)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "C:\Users\injemam\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\db\backends\sqlite3\base.py", line 383, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: blog_category

请帮助如何消除此错误？ 我是 Django 的新手，我从 Github 克隆了这个项目 https://github.com/Williano/Bona-Blog

使用 Django-2.2

【问题讨论】：

标签： python django django-2.2

【解决方案1】：

显然，

您手动更改了数据库表（例如通过数据库接口）
您缺少一个或多个必需的迁移文件。

我建议你在开发环境中

删除数据库
重新创建数据库
然后再python manage.py migrate

【讨论】：

是的，我做到了，但它不起作用。仍然有同样的错误。

【解决方案2】：

这似乎是博客软件中的一个错误。

创建迁移时，代码中的模型会被内省，在此过程中，许多模块会随模型一起导入。在软件中有一个点是在导入时进行查询（article_forms.py，line 40。此时查询指向的表还不存在并且失败。

作者可能没有注意到这个错误，因为他/她在进行更改时已经有了桌子。而且他/她从未从头开始创建新实例。

您应该将其报告为错误。

【讨论】：

我该如何解决这个问题，因为我是 django 的新手。请给我一些建议。
请重新考虑我的最后一段！

【解决方案3】：

由于您处于开发阶段，您可以删除数据库并重新创建它。但在重新创建之前删除所有应用程序上的所有以前的迁移文件。确保这些文件夹中只有 lnlt 文件

【讨论】：

检查所有应用程序，其中一些文件或。 pyc 文件在那里
我删除了 db、所有迁移文件和 .pyc 文件，但也没有用。
一个称为博客的应用程序。看到这个回购link

【解决方案4】：

python manage.py makemigrations
python manage.py 迁移

这已经帮我解决了！

【讨论】：

【解决方案5】：

这个问题很老，但我提出了一个对我有用的解决方案，因为其他人还没有提到它。此外，这可能只是一条评论，但我需要 50 个声誉才能发表评论，而在撰写本文时我还没有。

不要运行项目范围的迁移，而是使其特定于博客应用：

python manage.py makemigrations blog
python manage.py migrate blog

为您的其他应用执行此操作。

【讨论】：