python异步操作MySQL（aiomysql）

原文链接https://pypi.org/project/aiomysql/

aiomysql是用于从asyncio（PEP-3156 / tulip）框架访问MySQL数据库的“驱动程序”。 它依赖并重用了PyMySQL的大部分内容。 aiomysql试图成为类aiopg的库，并保留相同的api、外观和感觉。
内部的aiomysql是PyMySQL的副本，底层的io调用切换到async，基本上是在适当的地方产生和asyncio.coroutine。 sqlalchemy支持从aiopg移植。
文档https://aiomysql.readthedocs.io/

基本的异步connection

import asyncio
from aiomysql import create_pool


loop = asyncio.get_event_loop()

async def go():
    async with create_pool(host='127.0.0.1', port=3306,
                           user='root', password='',
                           db='mysql', loop=loop) as pool:
        async with pool.get() as conn:
            async with conn.cursor() as cur:
                await cur.execute("SELECT 42;")
                value = await cur.fetchone()
                print(value)


loop.run_until_complete(go())

连接 pool

import asyncio
import aiomysql


async def test_example(loop):
    pool = await aiomysql.create_pool(host='127.0.0.1', port=3306,
                                      user='root', password='',
                                      db='mysql', loop=loop)
    async with pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute("SELECT 42;")
            print(cur.description)
            (r,) = await cur.fetchone()
            assert r == 42
    pool.close()
    await pool.wait_closed()


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

对象关系映射SQLAlchemy - Object Relationship Mapping

import asyncio
import sqlalchemy as sa

from aiomysql.sa import create_engine


metadata = sa.MetaData()

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


async def go(loop):
    engine = await create_engine(user='root', db='test_pymysql',
                                 host='127.0.0.1', password='', loop=loop)
    async with engine.acquire() as conn:
        await conn.execute(tbl.insert().values(val='abc'))
        await conn.execute(tbl.insert().values(val='xyz'))

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

    engine.close()
    await engine.wait_closed()


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