How to make SQLAlchemy in Tornado to be async?

Question

How to make SQLAlchemy in Tornado to be async ? I found example for MongoDB on async mongo example but I couldn\'t find anything like

Answer 1

I had this same issue in the past and I couldn't find a reliable Async-MySQL library. However there is a cool solution using Asyncio + Postgres. You just need to use the aiopg library, which comes with SQLAlchemy support out of the box:

import asyncio
from aiopg.sa import create_engine
import sqlalchemy as sa

metadata = sa.MetaData()

tbl = sa.Table('tbl', metadata,
    sa.Column('id', sa.Integer, primary_key=True),
    sa.Column('val', sa.String(255)))

async def create_table(engine):
    async with engine.acquire() as conn:
        await conn.execute('DROP TABLE IF EXISTS tbl')
        await conn.execute('''CREATE TABLE tbl (
                                  id serial PRIMARY KEY,
                                  val varchar(255))''')

async def go():
    async with create_engine(user='aiopg',
                             database='aiopg',
                             host='127.0.0.1',
                             password='passwd') as engine:

        async with engine.acquire() as conn:
            await conn.execute(tbl.insert().values(val='abc'))

            async for row in conn.execute(tbl.select()):
                print(row.id, row.val)

loop = asyncio.get_event_loop()
loop.run_until_complete(go())

Updated as mentioned by @cglacet