如何在Django中使用多个数据库

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'default_db',
        'USER': 'root',
        'PASSWORD': 'password',
        'HOST': 'localhost',
        'PORT': '3306',
    },
    'secondary': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'secondary_db',
        'USER': 'root',
        'PASSWORD': 'password',
        'HOST': 'localhost',
        'PORT': '3306',
    }
}

class PrimaryRouter:
    """
    A router to control all database operations on models in the
    primary application.
    """
    def db_for_read(self, model, **hints):
        if model._meta.app_label == 'primary':
            return 'secondary'
        return 'default'

    def db_for_write(self, model, **hints):
        if model._meta.app_label == 'primary':
            return 'secondary'
        return 'default'

    def allow_relation(self, obj1, obj2, **hints):
        if obj1._meta.app_label == 'primary' or obj2._meta.app_label == 'primary':
            return True
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label == 'primary':
            return db == 'secondary'
        return None


class SecondaryRouter:
    """
    A router to control all database operations on models in the
    secondary application.
    """
    def db_for_read(self, model, **hints):
        if model._meta.app_label == 'secondary':
            return 'secondary'
        return 'default'

    def db_for_write(self, model, **hints):
        if model._meta.app_label == 'secondary':
            return 'secondary'
        return 'default'

    def allow_relation(self, obj1, obj2, **hints):
        if obj1._meta.app_label == 'secondary' or obj2._meta.app_label == 'secondary':
            return True
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label == 'secondary':
            return db == 'secondary'
        return None

DATABASE_ROUTERS = ['myproject.routers.PrimaryRouter', 'myproject.routers.SecondaryRouter']

class MyModel(models.Model):
    # 使用secondary数据库连接
    objects = models.Manager(using='secondary')