一、场景与思路
同一个项目中需要连接多个数据库。
二、代码
代码中主要是三个部分，settings、models以及自己写的一个类。
1.自己写的文件：database_app_router.py 类名：DatabaseAppsRouter
# database_app_router.py # -*- coding: utf-8 -*- from django.conf import settings DATABASE_MAPPING = settings.DATABASES_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.""" """将所有读操作指向特定的数据库。""" 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.""" """将所有写操作指向特定的数据库。""" 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.""" """允许使用相同数据库的应用程序之间的任何关系""" 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 else: return None def allow_syncdb(self, db, model): """Make sure that apps only appear in the related database.""" """确保这些应用程序只出现在相关的数据库中。""" if db in DATABASE_MAPPING.values(): return DATABASE_MAPPING.get(model._meta.app_label) == db elif model._meta.app_label in DATABASE_MAPPING: return False return None def allow_migrate(self, db, app_label, model=None, **hints): """Make sure the auth app only appears in the 'auth_db' database.""" """确保身份验证应用程序只出现在“authdb”数据库中。""" if db in DATABASE_MAPPING.values(): return DATABASE_MAPPING.get(app_label) == db elif app_label in DATABASE_MAPPING: return False return None
settings.py文件中修改
# settings.py DATABASES = { "default": { "ENGINE": "django.db.backends.mysql", "NAME": "integral_wall", "USER": "root", "PASSWORD": "123456", "HOST": "127.0.0.1", "PORT": "3306", }, "sdk_51zhuan": { "ENGINE": "django.db.backends.mysql", "NAME": "sdk_51zhuan", "USER": "root", "PASSWORD": "123456", "HOST": "127.0.0.1", "PORT": "3306", }, } DATABASES_APPS_MAPPING = { 'integral_wall': 'default', 'sdk_db': 'sdk_51zhuan',
'admin': 'sdk_51zhuan',
'auth': 'sdk_51zhuan',
} DATABASE_ROUTERS = ['integral_wall_manager.database_app_router.DatabaseAppsRouter']
models.py文件修改
# models.py class SdkApplication(models.Model): """ 应用程序列表 """ sdk_type_choices = ( (0, '不合作'), (1, '一定时间内合作'), (2, '永久合作'), ) id = models.AutoField(primary_key=True) app_id = models.CharField('苹果商店里的APP id', max_length=16, default='') app_name = models.CharField('应用名称', max_length=64) bundle_id = models.CharField('包ID，域名倒序', max_length=64, default='') create_time = models.DateTimeField('创建时间', auto_now_add=True) class Meta: app_label = 'sdk_db' # 连接的数据库 db_table = "sdk_application" # 表名 class AdRecord(models.Model): """ 广告记录 """ type = models.CharField('操作类型', max_length=16) action = models.CharField('操作、行为', max_length=16) create_time = models.DateTimeField('创建时间', auto_now_add=True) class Meta: # app_label 不写，使用默认 db_table = "ad_record" # 表名
三、执行
执行的顺序就是大家熟悉的了：
1.python manage.py makemigrations
之后的稍有不同：
2.python manage.py migrate --database=sdk_51zhuan
......
python manage.py migrate（只有默认数据库不为空时才可以这么实用，若为空则是用上面的方法）
其实在这里没有特别的执行顺序，但是我个人建议大家是最后执行migrate（即默认数据库）。另外要注意一点，admin、auth是一定要在一个app里被makemigrations放到一个XXXX_initial.py文件中的，不然你怎么migrate都不会有这些Django自建的表的！