为什么Python MySQL插入表不起作用？

Question

我正在使用aiomysql和MariaDB。我可以创建表或选择数据，但无法将数据插入表中。如果您使用

SELECT

fetchall()

数据，那么它将显示您刚刚插入的内容，但立即从数据库中删除。

async def test_example(loop):
    pool = await aiomysql.create_pool(host='127.0.0.1', port=3306,
                                      user='root', password='',
                                      db='test', loop=loop)
    async with pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute("INSERT INTO `tbl`(`id`, `val`) VALUES (37, 'z');")
            print(cur.fetchall())
    pool.close()
    await pool.wait_closed()

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

为什么？

Answer 1

来自 PEP-249 规范：

.fetchall()

获取查询结果的所有（剩余）行，将它们作为序列序列（例如元组列表）返回。

由于 sql

INSERT

语句不会生成结果集，因此在尝试从数据库服务器获取信息之前，您应该尝试使用

SELECT

语句。

Answer 2

也许你的数据库配置了自动提交 ́_(ツ)_/́

Answer 3

删除表名和列名中的引号。

import aiomysql
import asyncio


async def select(loop, sql, pool):
    async with pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute(sql)
            r = await cur.fetchone()
            print(r)


async def insert(loop, sql, pool):
    async with pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute(sql)
            await conn.commit()


async def main(loop):
    pool = await aiomysql.create_pool(host='127.0.0.1', port=3306,
                                      user='root', password='',
                                      db='test', loop=loop)
    c1 = select(loop=loop, sql='select * from tbl', pool=pool)
    c2 = insert(loop=loop, sql="INSERT INTO tbl(id, val) VALUES (37, 'z');", pool=pool)

    tasks = [asyncio.ensure_future(c1), asyncio.ensure_future(c2)]
    return await asyncio.gather(*tasks)


if __name__ == '__main__':
    cur_loop = asyncio.get_event_loop()
    cur_loop.run_until_complete(main(cur_loop))