python pymysql设置autocommit false失败

Question

我的脚本从文件中读取 MYSQL UPDATE 查询，然后应该使用 autocommit = 0 立即执行它们。但是，如果我删除 conn.commit() 它仍然会一个接一个地运行，尽管我没有 promise 。错误在哪里？

import pymysql
conn = pymysql.connect(host='x', unix_socket='/tmp/mysql.sock',user='x', passwd='x', db='x')
fileHandle = open ( 'mysqlout.txt' )
fileList = fileHandle.readlines()
fileHandle.close()
i = 1
weiter = input("Execute MYSQL file? ")
if (weiter == 'y'):
    cur = conn.cursor()
    cur.execute('SET autocommit = 0')
    conn.commit()
    for fileLine in fileList: #-----each line is an UPDATE...query
        cur.execute(fileLine)
        i = i + 1
        print(i," ---",round(i / len(fileList),3))
#conn.commit()
conn.close()

Answer 1

MySQL 中的 MyISAM 存储引擎不支持事务。只有 InnoDB 支持 ACID 事务。

引用 Transactions and Atomic Operations MySQL documentation :

In transactional terms, MyISAM tables effectively always operate in autocommit = 1 mode.

你应该 check storage engine for your tables :

mysql> SELECT table_name,engine FROM INFORMATION_SCHEMA.TABLES 
       WHERE table_schema=DATABASE();
+--------------+--------+
| table_name   | engine |
+--------------+--------+
| stats        | MyISAM |
+--------------+--------+
1 row in set (0.00 sec)

将表格移动到 MySQL storage engine支持交易。