python非同步操作MySQL(aiomysql)
阿新 • • 發佈:2019-01-25
aiomysql是用於從asyncio(PEP-3156 / tulip)框架訪問MySQL資料庫的“驅動程式”。 它依賴並重用了PyMySQL的大部分內容。 aiomysql試圖成為類aiopg的庫,並保留相同的api、外觀和感覺。
內部的aiomysql是PyMySQL的副本,底層的io呼叫切換到async,基本上是在適當的地方產生和asyncio.coroutine。 sqlalchemy支援從aiopg移植。
文件https://aiomysql.readthedocs.io/
基本的非同步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())
連線 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))
物件關係對映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))