simple aiogram middleware for passing db sessions

from typing import Callable, Dict, Any, Awaitable

from aiogram import BaseMiddleware
from aiogram.types import TelegramObject
from sqlalchemy.ext.asyncio import async_sessionmaker

from bot.db.requests import Database  # your class with database queries


class DbMiddleware(BaseMiddleware):
    def __init__(self, session_factory: async_sessionmaker):
        self.factory = session_factory

    async def __call__(
        self,
        handler: Callable[[TelegramObject, Dict[str, Any]], Awaitable[Any]],
        event: TelegramObject,
        data: Dict[str, Any],
    ) -> Any:
        async with self.factory() as session:
            data['db'] = Database(session)
            return await handler(event, data)