Django中多数据库的使用

Posted 2022-06-13 stormztt

django中，你可以为每一个app都单独设置一个数据库。

 

一、在项目project下新建文件database_router.py文件：

DATABASE_MAPPING = ‘app1‘: ‘db1‘,‘app2‘:‘db2‘
class DatabaseAppsRouter(object):    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=None, **hints):        """        Make sure the auth app only appears in the ‘auth_db‘        database.        """        if db in DATABASE_MAPPING.values():            return DATABASE_MAPPING.get(app_label) == db        elif app_label in DATABASE_MAPPING:            return False        return None

 

二、settings.py

2.1 数据库配置

DATABASES = ABASES =     ‘default‘:         ‘ENGINE‘: ‘django.db.backends.sqlite3‘,        ‘NAME‘: os.path.join(BASE_DIR, ‘db.sqlite3‘),    ,    ‘db1‘:         ‘ENGINE‘: ‘django.db.backends.mysql‘,        ‘NAME‘: ‘dbname1‘,        ‘USER‘: ‘your_db_user_name‘,        ‘PASSWORD‘: ‘yourpassword‘,        "HOST": "localhost",    ,    ‘db2‘:         ‘ENGINE‘: ‘django.db.backends.mysql‘,        ‘NAME‘: ‘dbname2‘,        ‘USER‘: ‘your_db_user_name‘,        ‘PASSWORD‘: ‘yourpassword‘,        "HOST": "localhost",    ,

2.2 router配置

DATABASE_ROUTERS = [‘project_name.database_router.DatabaseAppsRouter‘]

 

三、使用时数据库同步

python manage.py migrate --database=db1
python manage.py migrate --database=db2