回答之前：是的我已经拥有＆＃39; constance.backends.database＆＃39;在我的INSTALLED_APPS和CONSTANCE_CONFIG中，按照默认实现
我刚刚设置了一个拥有django-constance的现有项目 ＆＃34; https://github.com/jazzband/django-constance＆＃34;
当我进行迁移或迁移时，我得到以下异常：
Traceback (most recent call last):
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
psycopg2.ProgrammingError: relation "constance_config" does not exist
LINE 1: ...ce_config"."key", "constance_config"."value" FROM "constance...
^
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
utility.execute()
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/management/__init__.py", line 359, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/management/base.py", line 294, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/management/base.py", line 342, in execute
self.check()
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/management/base.py", line 374, in check
include_deployment_checks=include_deployment_checks,
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/management/base.py", line 361, in _run_checks
return checks.run_checks(**kwargs)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/checks/registry.py", line 81, in run_checks
new_errors = check(app_configs=app_configs)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/checks/urls.py", line 14, in check_url_config
return check_resolver(resolver)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/core/checks/urls.py", line 24, in check_resolver
for pattern in resolver.url_patterns:
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/urls/resolvers.py", line 313, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/urls/resolvers.py", line 306, 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 "/home/saad/PycharmProjects/Sentimeter/sentimeter-backend/backend/urls.py", line 22, in <module>
from backend.dashboard import urls as dashboard_urls
File "/home/saad/PycharmProjects/Sentimeter/sentimeter-backend/backend/dashboard/urls.py", line 3, in <module>
from backend.dashboard.views.benchmark import BenchmarkView
File "/home/saad/PycharmProjects/Sentimeter/sentimeter-backend/backend/dashboard/views/benchmark.py", line 9, in <module>
from sentimeter.services.dates import DateService
File "/home/saad/PycharmProjects/Sentimeter/sentimeter-backend/sentimeter/services/dates.py", line 8, in <module>
class DateService:
File "/home/saad/PycharmProjects/Sentimeter/sentimeter-backend/sentimeter/services/dates.py", line 19, in DateService
def get_dates(days=config.DEFAULT_NO_OF_DAYS, start_date=None, end_date=None):
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/utils/functional.py", line 235, in inner
return func(self._wrapped, *args)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/constance/base.py", line 19, in __getattr__
result = self._backend.get(key)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/constance/backends/database/__init__.py", line 71, in get
value = self._model._default_manager.get(key=key).value
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/models/manager.py", line 85, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/models/query.py", line 379, in get
num = len(clone)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/models/query.py", line 238, in __len__
self._fetch_all()
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/models/query.py", line 1087, in _fetch_all
self._result_cache = list(self.iterator())
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/models/query.py", line 54, in __iter__
results = compiler.execute_sql()
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/models/sql/compiler.py", line 835, in execute_sql
cursor.execute(sql, params)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/home/saad/virtualenvs/sentimeter_backend/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: relation "constance_config" does not exist
LINE 1: ...ce_config"."key", "constance_config"."value" FROM "constance...
^
答案 0 :(得分：0)
之前我遇到过这种情况。
这是解决此问题的步骤。
我删除所有constance配置（CONSTANCE_CONFIG）以及使用from constance import config
唯一剩下的constance代码就像是
INSTALLED_APPS = (
...
'constance',
'constance.backends.database',
...
)
...
CONSTANCE_BACKEND = 'constance.backends.database.DatabaseBackend'
...
之后我能够运行migrate