问题
OK, I'm stumped. I think I've tried everything.
I created a model in an app's models.py and also added some more fields to an existing model (all with default values). Then I ran makemigrations. The result:
$ python3 manage.py makemigrations
Traceback (most recent call last):
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/sqlite3/base.py", line 323, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such column: myapp_MyExistingModel.first_new_field
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 14, in <module>
execute_from_command_line(sys.argv)
File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
utility.execute()
File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 345, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/usr/local/lib/python3.5/dist-packages/django/core/management/base.py", line 348, in run_from_argv
self.execute(*args, **cmd_options)
File "/usr/local/lib/python3.5/dist-packages/django/core/management/base.py", line 398, in execute
self.check()
File "/usr/local/lib/python3.5/dist-packages/django/core/management/base.py", line 426, in check
include_deployment_checks=include_deployment_checks,
File "/usr/local/lib/python3.5/dist-packages/django/core/checks/registry.py", line 75, in run_checks
new_errors = check(app_configs=app_configs)
File "/usr/local/lib/python3.5/dist-packages/django/core/checks/urls.py", line 13, in check_url_config
return check_resolver(resolver)
File "/usr/local/lib/python3.5/dist-packages/django/core/checks/urls.py", line 23, in check_resolver
for pattern in resolver.url_patterns:
File "/usr/local/lib/python3.5/dist-packages/django/utils/functional.py", line 33, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/usr/local/lib/python3.5/dist-packages/django/core/urlresolvers.py", line 417, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/usr/local/lib/python3.5/dist-packages/django/utils/functional.py", line 33, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/usr/local/lib/python3.5/dist-packages/django/core/urlresolvers.py", line 410, in urlconf_module
return import_module(self.urlconf_name)
File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 986, in _gcd_import
File "<frozen importlib._bootstrap>", line 969, in _find_and_load
File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 665, in exec_module
File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
File "/path/to/myproject/myproject/urls.py", line 49, in <module>
url(r'^someurl/', include('myapp.urls')),
File "/usr/local/lib/python3.5/dist-packages/django/conf/urls/__init__.py", line 52, in include
urlconf_module = import_module(urlconf_module)
File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 986, in _gcd_import
File "<frozen importlib._bootstrap>", line 969, in _find_and_load
File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 665, in exec_module
File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
File "/path/to/myproject/myapp/urls.py", line 2, in <module>
from . import views
File "/path/to/myproject/myapp/views.py", line 8, in <module>
existing_model = MyExistingModel.objects.all()[0]
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 297, in __getitem__
return list(qs)[0]
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 258, in __iter__
self._fetch_all()
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 1074, in _fetch_all
self._result_cache = list(self.iterator())
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 52, in __iter__
results = compiler.execute_sql()
File "/usr/local/lib/python3.5/dist-packages/django/db/models/sql/compiler.py", line 848, in execute_sql
cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/utils.py", line 95, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/usr/local/lib/python3.5/dist-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/sqlite3/base.py", line 323, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such column: myapp_MyExistingModel.first_new_field
If it matters, I'm using Mezzanine CMS and MyExistingModel is an extension of its Page class. It only has one instance.
So here's what I tried next:
manage.py migrate --fakemanage.py flush- Renaming my database so a new one would be created
All of these threw the same traceback. I went into the last migration for the app. It contained an AddModel for my new model and a RemoveField for a field in the old model I renamed, but no AddField for the new fields I created. So I added them to the migrations file manually and retried manage.py migrate --fake. Same traceback. I tried all the other commands too. Same traceback.
Finally, I deleted all the app's migrations, leaving just __init__.py. I also renamed the database so it would be recreated. I retried flush, makemigrations, and migrate (with and without --fake). All of these resulted in this traceback:
Traceback (most recent call last):
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/sqlite3/base.py", line 323, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such table: myapp_MyExistingModel
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 14, in <module>
execute_from_command_line(sys.argv)
File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
utility.execute()
File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 345, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/usr/local/lib/python3.5/dist-packages/django/core/management/base.py", line 348, in run_from_argv
self.execute(*args, **cmd_options)
File "/usr/local/lib/python3.5/dist-packages/django/core/management/base.py", line 398, in execute
self.check()
File "/usr/local/lib/python3.5/dist-packages/django/core/management/base.py", line 426, in check
include_deployment_checks=include_deployment_checks,
File "/usr/local/lib/python3.5/dist-packages/django/core/checks/registry.py", line 75, in run_checks
new_errors = check(app_configs=app_configs)
File "/usr/local/lib/python3.5/dist-packages/django/core/checks/urls.py", line 13, in check_url_config
return check_resolver(resolver)
File "/usr/local/lib/python3.5/dist-packages/django/core/checks/urls.py", line 23, in check_resolver
for pattern in resolver.url_patterns:
File "/usr/local/lib/python3.5/dist-packages/django/utils/functional.py", line 33, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/usr/local/lib/python3.5/dist-packages/django/core/urlresolvers.py", line 417, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/usr/local/lib/python3.5/dist-packages/django/utils/functional.py", line 33, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/usr/local/lib/python3.5/dist-packages/django/core/urlresolvers.py", line 410, in urlconf_module
return import_module(self.urlconf_name)
File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 986, in _gcd_import
File "<frozen importlib._bootstrap>", line 969, in _find_and_load
File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 665, in exec_module
File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
File "/path/to/myproject/myproject/urls.py", line 49, in <module>
url(r'^someurl/', include('myapp.urls')),
File "/usr/local/lib/python3.5/dist-packages/django/conf/urls/__init__.py", line 52, in include
urlconf_module = import_module(urlconf_module)
File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 986, in _gcd_import
File "<frozen importlib._bootstrap>", line 969, in _find_and_load
File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 665, in exec_module
File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
File "/path/to/myproject/myapp/urls.py", line 2, in <module>
from . import views
File "/path/to/myproject/myapp/views.py", line 8, in <module>
existing_model = MyExistingModel.objects.all()[0]
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 297, in __getitem__
return list(qs)[0]
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 258, in __iter__
self._fetch_all()
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 1074, in _fetch_all
self._result_cache = list(self.iterator())
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 52, in __iter__
results = compiler.execute_sql()
File "/usr/local/lib/python3.5/dist-packages/django/db/models/sql/compiler.py", line 848, in execute_sql
cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/utils.py", line 95, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/usr/local/lib/python3.5/dist-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/sqlite3/base.py", line 323, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: myapp_MyExistingModel
At this point, I have no idea what to even try next, except start over. Any suggestions are appreciated.
回答1:
I figured it out! Lesson learned: read the whole stacktrace, not just the last line. In this case, the offensive line was in my views.py:
File "/path/to/myproject/myapp/views.py", line 8, in <module>
existing_model = MyExistingModel.objects.all()[0]
Like I said, MyExistingModel has only one instance, and this line set that instance to the local variable existing_model for use in the views.py code.
I still don't understand why makemigrations would need to run views.py. But it does, apparently! In doing so, MyExistingModel was imported from models.py, including the new fields. But those fields hadn't yet been migrated. Thus, OperationalError.
来源：https://stackoverflow.com/questions/38564851/django-db-utils-operationalerror-no-matter-what-i-try