django.db.utils.ProgrammingError：表不存在

Question

我使用了两个数据库，一个是默认的sqlite3，另一个是mysql。我刚刚在名为theapp 的应用程序下创建了一个模型帖子。我还创建了 routers.py。

这是 settings.py

DATABASES = {
    'default': {
       'ENGINE': 'django.db.backends.sqlite3',
       'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    },

    'customer': {
       'NAME': 'customer',
       'ENGINE': 'django.db.backends.mysql',
       'USER': 'root',
       'PASSWORD': 'haha',
    }
 }

这是 routers.py

class CustomerRouter:
"""
A router to control all database operations on models in the
auth application.
"""
def db_for_read(self, model, **hints):
    """
    Attempts to read auth models go to auth_db.
    """
    if model._meta.app_label == 'theapp':
        return 'customer'
    return None

def db_for_write(self, model, **hints):
    """
    Attempts to write auth models go to auth_db.
    """
    if model._meta.app_label == 'theapp':
        return 'customer'
    return None

def allow_relation(self, obj1, obj2, **hints):
    """
    Allow relations if a model in the auth app is involved.
    """        
    if obj1._meta.app_label == 'theapp' or \
       obj2._meta.app_label == 'theapp':
       return True
    return None

def allow_migrate(self, db, app_label, model_name=None, **hints):
    """
    Make sure the auth app only appears in the 'auth_db'
    database.
    """
    if app_label == 'theapp':
        return db == 'customer'
    return None

这是我的 models.py

from django.db import models
from django.utils import timezone


class Post(models.Model):
    author = models.ForeignKey('auth.User', on_delete=models.CASCADE)
    title = models.CharField(max_length=200)
    text = models.TextField()
    created_date = models.DateTimeField(
        default=timezone.now)
    published_date = models.DateTimeField(
        blank=True, null=True)

    def publish(self):
        self.published_date = timezone.now()
        self.save()

    def __str__(self):
        return self.title

当我尝试在管理面板中打开帖子表时会发生这种情况

有什么想法吗？

Answer 1

出于某种原因，Django 有时会要求您这样做

python manage.py makemigrations <application>

之前

python manage.py migrate <application>

确保在运行命令之前删除 migrations 和 __pychache__ 文件夹。

Answer 2

我认为您尚未在 MySQL 数据库上运行迁移，

试试

python manage.py migrate --database=customer

阅读https://docs.djangoproject.com/en/1.11/ref/django-admin/#migrate

Answer 3

就我而言，我有两个数据库托管在两个不同的服务器上。这两个数据库都可以使用 MySQL，但它与使用 SQLLite-MySQL 的情况相同。

也许这个例子可以解决你的问题，所以我在我的 Django Web 应用程序中显示我所拥有的。

到我的settings.py 文件中类似这样的内容：

DATABASES = {

    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'default',
        'USER': 'osx',
        'PASSWORD': '******',
        'HOST': '172.30.10.12',
        'PORT': '3306',
        'OPTIONS': {
            'init_command': 'SET innodb_strict_mode=1',
            'sql_mode': 'traditional',
        }
    },


    'DS2': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'DS2',
        'USER': 'osx',
        'PASSWORD': '******',
        'HOST': '172.30.10.13',
        'PORT': '3306',
        'OPTIONS': {
            'init_command': 'SET innodb_strict_mode=1',
            'sql_mode': 'traditional',
        }
    }
}


BDD = ('default', 'DS2')
DATABASE_ROUTERS = ['MyApp.routersLocal.LocalRouter', 'MyApp.routersGlobal.GlobalRouter']

然后我有两个文件：routersGlobal.py 和 routersLocal.py：

#routersGlobal.py

from django.conf import settings

class GlobalRouter(object):
    """
A router to control all database operations on models in the
auth application.
"""

    def db_for_read(self, model, **hints):
        """
        Attempts to read auth models go to auth.
        """
        app_list = ('Identity',)

        if model._meta.app_label in app_list:
            return 'DS2'
        return None

    def db_for_write(self, model, **hints):
        """
        Attempts to write auth models go to auth.
        """
        app_list = ('Identity',)
        if model._meta.app_label in app_list:
            return 'DS2'
        return None

    def allow_relation(self, obj1, obj2, **hints):
        """
        Allow relations if a model in the auth app is involved.
        """
        app_list = ('Identity',)
        if obj1._meta.app_label in app_list and obj2._meta.app_label in app_list:
            return 'DS2'
        return None

    def allow_migrate(self, db, app_label, model=None, **hints):
        """
        Make sure the auth app only appears in the 'auth'
        database.
        """
        app_list = ('Identity',)

        if app_label in app_list:
            return db == 'DS2'
        return None

和

#routersLocal.py
from django.conf import settings

class LocalRouter(object):
    """
A router to control all database operations on models in the
auth application.
"""

    def db_for_read(self, model, **hints):
        """
        Attempts to read auth models go to auth.
        """
        app_list = ('auth', 'admin', 'contenttypes', 'sessions', 'Configurations', 'log', 'Home', 'DSCORE', 'Informations')

        if model._meta.app_label in app_list:
            return 'default'
        return None

    def db_for_write(self, model, **hints):
        """
        Attempts to write auth models go to auth.
        """
        app_list = ('auth', 'admin', 'contenttypes', 'sessions', 'Configurations', 'log', 'Home', 'DSCORE', 'Informations')
        if model._meta.app_label in app_list:
            return 'default'
        return None

    def allow_relation(self, obj1, obj2, **hints):
        """
        Allow relations if a model in the auth app is involved.
        """
        app_list = ('auth', 'admin', 'contenttypes', 'sessions', 'Configurations', 'log', 'Home', 'DSCORE', 'Informations')
        if obj1._meta.app_label in app_list and obj2._meta.app_label in app_list:
            return True
        return None

    def allow_migrate(self, db, app_label, model=None, **hints):
        """
        Make sure the auth app only appears in the 'auth'
        database.
        """
        app_list = ('auth', 'admin', 'contenttypes', 'sessions', 'Configurations', 'log', 'Home', 'DSCORE', 'Informations')

        if app_label in app_list:
            return db == 'default'
        return None 

编辑：

makemigrations 和 migrate 是你制作的吗？