python - ImproperlyConfigured : settings. 数据库配置不正确。请提供引擎值

Question

我正在 Heroku 上设置我的 Django 项目。我一直在关注文档，但是当我 foreman start 时，我收到一个我不太明白的错误。我已经设置了我的引擎文件，但它似乎并不想工作。

完整回溯:

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/__init__.py", line 399, in execute_from_command_line
    utility.execute()
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/__init__.py", line 392, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/base.py", line 242, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/base.py", line 285, in execute
    output = self.handle(*args, **options)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/base.py", line 415, in handle
    return self.handle_noargs(**options)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/commands/syncdb.py", line 57, in handle_noargs
    cursor = connection.cursor()
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/db/backends/__init__.py", line 160, in cursor
    cursor = self.make_debug_cursor(self._cursor())
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/db/backends/dummy/base.py", line 15, in complain
    raise ImproperlyConfigured("settings.DATABASES is improperly configured. "
django.core.exceptions.ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.

有人建议使用 ./manage.py diffsettings 并显示 DATABASES 部分:

DATABASES = {'default': {'AUTOCOMMIT': True, 'ENGINE': 'django.db.backends.dummy', 'ATOMIC_REQUESTS': False, 'NAME': '', 'TEST_MIRROR': None, 'CONN_MAX_AGE': 0, 'TEST_NAME': None, 'TIME_ZONE': 'UTC', 'TEST_COLLATION': None, 'PORT': '', 'HOST': '', 'USER': '', 'TEST_CHARSET': None, 'PASSWORD': '', 'OPTIONS': {}}}

我似乎无法弄清楚它是什么意思，但从表面上看并不正确。

这是我认为可能与此问题相关的 settings.py 的一部分:

import os
import dj_database_url

ON_HEROKU = os.environ.get('ON_HEROKU')
HEROKU_SERVER = os.environ.get('HEROKU_SERVER')

if ON_HEROKU:
    
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': 'postgresql',
        }
    }
else:
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
            'USER': '',
            'PASSWORD': '',
            'HOST': '',                      # Empty for localhost through domain sockets or '127.0.0.1' for localhost through TCP.
            'PORT': '',  
        }
    }


DATABASES['default'] =  dj_database_url.config()

SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')

ALLOWED_HOSTS = ['*']

STATIC_URL = '/static/'

# only refers to the location where your static files should end up after running manage.py collectstatic. you shouldn't really need collectstatic) when developing locally
STATIC_ROOT = 'staticfiles'


STATICFILES_DIRS = (    
    os.path.join(BASE_DIR, '../static'),
)

Answer 1

您正在使用 dj-database-url module设置 DATABASES['default']。该行之前的任何内容:

DATABASES['default'] =  dj_database_url.config()

是没有意义的，因为您完全替换了数据库配置。 dj_database_url.config() 从 DATABASE_URL 环境变量加载您的数据库配置，如果未设置该变量，则返回 {}。

根据您的错误判断，您根本没有设置 DATABASE_URL。从 dj_database_url.config() 行之前的代码来看，您根本不应该使用 dj_database_url.config() 函数。

如果您确实想使用它，至少要构建一个默认 URL:

if ON_HEROKU:
    DATABASE_URL = 'postgresql://<postgresql>'
else:
    DATABASE_URL = 'sqlite:///' + os.path.join(BASE_DIR, 'db.sqlite3')

DATABASES = {'default': dj_database_url.config(default=DATABASE_URL)}