【发布时间】:2021-07-05 10:49:02
【问题描述】:
我试图通过在 Django 上使用 make migrations 向数据库表中添加一个新列,但有点不起作用,我遇到了一些奇怪的错误。根据另一篇 SO 帖子的建议,我使用 DROP TABLE 删除表并重新开始。
问题是,现在当我尝试迁移表时,它没有出现在我的 PostgreSQL 数据库中。当我检查make migrations 时,我没有得到任何要迁移的更改,表明它已同步。我也跑了:python3 manage.py migrate --run-syncdb,但仍然没有运气。
如果有任何帮助,我将不胜感激。
class UserVenue(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
venue = models.ForeignKey(mapCafes, on_delete=models.PROTECT)
user_list = models.ForeignKey(UserList, on_delete=models.CASCADE)
class Meta:
unique_together = ['user_list','venue']
由于某种原因,我仍然可以在 Django Admin 中看到该表,但随后出现此错误:
Environment:
Request Method: GET
Request URL: http://127.0.0.1:8000/admin/testingland/uservenue/
Django Version: 3.1.7
Python Version: 3.8.5
Installed Applications:
['django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'django.contrib.gis',
'testingland',
'rest_framework',
'bootstrap_modal_forms']
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 (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
The above exception (relation "testingland_uservenue" does not exist
LINE 1: SELECT COUNT(*) AS "__count" FROM "testingland_uservenue"
^
) was the direct cause of the following exception:
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/core/handlers/exception.py", line 47, in inner
response = get_response(request)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/core/handlers/base.py", line 181, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/contrib/admin/options.py", line 614, in wrapper
return self.admin_site.admin_view(view)(*args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/utils/decorators.py", line 130, in _wrapped_view
response = view_func(request, *args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/views/decorators/cache.py", line 44, in _wrapped_view_func
response = view_func(request, *args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/contrib/admin/sites.py", line 233, in inner
return view(request, *args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/utils/decorators.py", line 43, in _wrapper
return bound_method(*args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/utils/decorators.py", line 130, in _wrapped_view
response = view_func(request, *args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/contrib/admin/options.py", line 1693, in changelist_view
cl = self.get_changelist_instance(request)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/contrib/admin/options.py", line 735, in get_changelist_instance
return ChangeList(
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/contrib/admin/views/main.py", line 100, in __init__
self.get_results(request)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/contrib/admin/views/main.py", line 235, in get_results
result_count = paginator.count
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/utils/functional.py", line 48, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/core/paginator.py", line 94, in count
return c()
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/models/query.py", line 411, in count
return self.query.get_count(using=self.db)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/models/sql/query.py", line 515, in get_count
number = obj.get_aggregation(using, ['__count'])['__count']
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/models/sql/query.py", line 500, in get_aggregation
result = compiler.execute_sql(SINGLE)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1156, in execute_sql
cursor.execute(sql, params)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/backends/utils.py", line 98, in execute
return super().execute(sql, params)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/backends/utils.py", line 66, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/backends/utils.py", line 75, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
Exception Type: ProgrammingError at /admin/testingland/uservenue/
Exception Value: relation "testingland_uservenue" does not exist
LINE 1: SELECT COUNT(*) AS "__count" FROM "testingland_uservenue"
^
【问题讨论】:
-
您在数据库中删除了表,但您的迁移仍然认为该表在那里,因此您的迁移也需要反映这一点。您可以将迁移重置为零并再次运行。
-
我明白了,如何将迁移重置为零?
-
不幸的是它仍然产生同样的错误。
标签: django postgresql django-models