python - Django 数据库路由器无法导入名称连接

Question

我对 Django 1.4(python 2.6)上的数据库路由器有疑问。我已按照文档(https://docs.djangoproject.com/en/dev/topics/db/multi-db/#automatic-database-routing)进行操作，但是当我运行我的服务器时，出现以下错误消息:

django.core.exceptions.ImproperlyConfigured: Error importing database router MyDBRouter: "cannot import name connection"

我的设置.py

DATABASES = {
    'default': {
        ...
    },
    'other' : {
        ...
    }
}
DATABASE_ROUTERS = ['core.models.MyDBRouter',]

这里是数据库路由代码:

class MyAppRouter(object):
    def db_for_read(self, model, **hints):
        "Point all operations on myapp models to 'other'"
        if model._meta.app_label == 'myapp':
            return 'other'
        return None

    def db_for_write(self, model, **hints):
        "Point all operations on myapp models to 'other'"
        if model._meta.app_label == 'myapp':
            return 'other'
        return None

    def allow_relation(self, obj1, obj2, **hints):
        "Allow any relation if a model in myapp is involved"
        if obj1._meta.app_label == 'myapp' or obj2._meta.app_label == 'myapp':
            return True
        return None

    def allow_syncdb(self, db, model):
        "Make sure the myapp app only appears on the 'other' db"
        if db == 'other':
            return model._meta.app_label == 'myapp'
        elif model._meta.app_label == 'myapp':
            return False
        return None

我已经尝试将 None 替换为“默认”，但它仍然不起作用。

Answer 1

我通过在 settings.py 中添加“from django.db import connections”解决了这个问题

151 # Database router                                                                                                                                       
152 from django.db import connections
153 DATABASE_ROUTERS         = ['core.models.MyDBRouter',]

现在服务器运行正常!但是 django 只是忽略了路由器 -> 要修复它，永远不要将路由器保存在模型中!创建新文件