django1.9:一个app对应一个数据库

步骤：

1、在工程同名目录下新建一个database_route.py文件，内容如下：

# -*- coding: utf-8 -*-

from django.conf import settings

DATABASE_MAPPING = settings.DATABASE_APPS_MAPPING

class DatabaseAppsRouter(object):

   """

   A router to control all database operations on models for different

   databases.

   In case an app is not set in settings.DATABASE_APPS_MAPPING, the router

   will fallback to the `default` database.

   Settings example:

   DATABASE_APPS_MAPPING = {'app1': 'db1', 'app2': 'db2'}

   """

   def db_for_read(self, model, **hints):

      """"Point all read operations to the specific database."""

      if model._meta.app_label in DATABASE_MAPPING:

         return DATABASE_MAPPING[model._meta.app_label]

      return None

   def db_for_write(self, model, **hints):

      """Point all write operations to the specific database."""

      if model._meta.app_label in DATABASE_MAPPING:

         return DATABASE_MAPPING[model._meta.app_label]

      return None

   def allow_relation(self, obj1, obj2, **hints):

      """Allow any relation between apps that use the same database."""

      db_obj1 = DATABASE_MAPPING.get(obj1._meta.app_label)

      db_obj2 = DATABASE_MAPPING.get(obj2._meta.app_label)

      if db_obj1 and db_obj2:

         if db_obj1 == db_obj2:

            return True

         else:

            return False

      return None

   def allow_migrate(self, db, app_label, model_name=None, **hints):

      # print(db, app_label, model_name, hints)

      if db in DATABASE_MAPPING.values():

         return DATABASE_MAPPING.get(app_label) == db

      elif app_label in DATABASE_MAPPING:

         return False

      return None

2、在工程目录下的setting中增加如下内容：

DATABASES = {

    'default': {

        'ENGINE': 'django.db.backends.mysql',

        'NAME': ',

        'USER': '',

        'PASSWORD': '',

        'HOST': '',

        'PORT': 3306

    },

 'db1':{

        'ENGINE': 'django.db.backends.mysql',

        'NAME': 'db1',

        'USER': '',

        'PASSWORD': '',

        'HOST': '',

        'PORT': 3306

    }

    'db2':{

        'ENGINE': 'django.db.backends.mysql',

        'NAME': 'db2',

        'USER': '',

        'PASSWORD': '',

        'HOST': '',

        'PORT': 3306

    }

}

DATABASE_ROUTERS = ['工程名.database_router.DatabaseAppsRouter']

DATABASE_APPS_MAPPING = {

    'app1': 'db1',

    'app2': 'db2',

}

3、执行

python manage.py makemigration app1

python manage.py migrate mvp --database=db1

python manage.py makemigration app2

python manage.py migrate mvp --database=db2

4、导出数据

python manage.py dumpdata app1 --database=app1_db >app1_data.json(注意app1_db指的是setting中的db1标题，不是指数据库名)

5、导入数据

python manage.py loaddata data.json --database=app1_db