Django 配置问题答案

【问题标题】：Django configuration issueDjango 配置问题
【发布时间】：2020-01-28 04:41:47
【问题描述】：

我已经安装了 Django 并且能够运行服务器并访问 Django 主页。但是当我添加模型类时，我在终端中收到以下错误。

RuntimeError：模型类 myproject.urls.Board 未声明显式 app_label 并且不在 INSTALLED_APPS 中的应用程序中。

这是我在 settings.py 中的代码

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [

    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',

    'boards',
]

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',
]

ROOT_URLCONF = 'myproject.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'myproject.wsgi.application'


# Database
# https://docs.djangoproject.com/en/1.11/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'pythondb',
        'USER' : 'root',
        'PASSWORD' : 'calpine',
        'HOST' : 'localhost',
        'PORT' : '3306',
    }
}


# Password validation
# https://docs.djangoproject.com/en/1.11/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/1.11/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.11/howto/static-files/

STATIC_URL = '/static/'

模型类

from django.db import models
from django.contrib.auth.models import User


class Board(models.Model):
    name = models.CharField(max_length=30, unique=True)
    description = models.CharField(max_length=100)


class Topic(models.Model):
    subject = models.CharField(max_length=255)
    last_updated = models.DateTimeField(auto_now_add=True)
    board = models.ForeignKey(Board, 
    related_name='topics',
    on_delete=models.DO_NOTHING)
    starter = models.ForeignKey(User, related_name='topics', on_delete=models.DO_NOTHING)


class Post(models.Model):
    message = models.TextField(max_length=4000)
    topic = models.ForeignKey(Topic, related_name='posts', on_delete=models.DO_NOTHING)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(null=True)
    created_by = models.ForeignKey(User, related_name='posts',on_delete=models.DO_NOTHING)
    updated_by = models.ForeignKey(User, null=True, related_name='+', on_delete=models.DO_NOTHING)

【问题讨论】：

请分享目录结构。我认为您没有在设置（安装的应用程序）中添加正确的应用程序名称。另外，分享错误日志。
你能分享你的网址吗
问题出现在 urls.py 文件中。我不小心将模型类移动到 urls.py 文件中。谢谢大家。

标签： django

【解决方案1】：

不小心从 urls.py 文件中删除了 urlpatterns。解决了问题并使 urlpatterns 正确

urlpatterns = [
    url(r'^$', views.home, name='home'),
    url(r'^boards/(?P<pk>\d+)/$', views.board_topics, name='board_topics'),
    url(r'^admin/', admin.site.urls),
]

谢谢

【讨论】：