The easiest way to use multiple databases is to set up a database routing scheme. The default routing scheme ensures that objects remain ‘sticky’ to their original database (i.e., an object retrieved from the foo database will be saved on the same database). The default routing scheme ensures that if a database isn’t specified, all queries fall back to the default database.


Define Router

Define a router is simple, you need just write a class that has db_for_read and db_for_write methods.

class Router:
    def db_for_read(self, model: Type[Model]):
        return "slave"

    def db_for_write(self, model: Type[Model]):
        return "master"

The two methods return a connection string defined in configuration.

Config Router

Just put it in configuration of tortoise or in Tortoise.init method.

config = {
    "connections": {"master": "sqlite:///tmp/test.db", "slave": "sqlite:///tmp/test.db"},
    "apps": {
        "models": {
            "models": ["__main__"],
            "default_connection": "master",
    "routers": ["path.Router"],
    "use_tz": False,
    "timezone": "UTC",
await Tortoise.init(config=config)
# or
routers = config.pop('routers')
await Tortoise.init(config=config, routers=routers)

After that, all select operations will use slave connection, all create/update/delete operations will use master connection.