Python 使用 MySQL 数据库进行事务处理完整示例

import mysql.connector
from mysql.connector import Error
def transfer_money(from_id, to_id, amount):
    """
    模拟转账的事务处理
    :param from_id: 转出账户ID
    :param to_id: 转入账户ID
    :param amount: 转账金额
    """
    connection = None
    try:
        # 1. 建立数据库连接
        connection = mysql.connector.connect(
            host='localhost',
            user='root',
            password='123456',
            database='test_db'
        )
        # 2. 关闭自动提交，开启手动事务控制
        connection.autocommit = False
        cursor = connection.cursor()
        # 3. 执行事务内的多个SQL操作
        # 步骤1：扣除转出账户金额
        deduct_sql = "UPDATE account SET balance = balance - %s WHERE id = %s"
        cursor.execute(deduct_sql, (amount, from_id))
        # 步骤2：增加转入账户金额
        add_sql = "UPDATE account SET balance = balance + %s WHERE id = %s"
        cursor.execute(add_sql, (amount, to_id))
        # 模拟异常（可取消注释测试回滚效果）
        # raise Error("模拟转账异常，触发回滚")
        # 4. 所有操作执行成功，提交事务
        connection.commit()
        print("转账成功！事务已提交")
    except Error as e:
        # 5. 发生异常，回滚事务（撤销所有已执行的SQL操作）
        if connection:
            connection.rollback()
        print(f"转账失败，事务已回滚！错误信息：{e}")
    finally:
        # 6. 释放资源（关闭游标和连接）
        if connection and connection.is_connected():
            cursor.close()
            # 恢复自动提交（可选，不影响，但规范）
            connection.autocommit = True
            connection.close()
            print("数据库连接已关闭")
# ==================== 测试前准备 ====================
# 先在MySQL中创建测试表和数据：
# CREATE DATABASE IF NOT EXISTS test_db;
# USE test_db;
# CREATE TABLE IF NOT EXISTS account (
#     id INT PRIMARY KEY,
#     name VARCHAR(50),
#     balance DECIMAL(10,2)
# );
# INSERT INTO account (id, name, balance) VALUES (1, '张三', 1000.00), (2, '李四', 500.00);
# ==================== 执行转账测试 ====================
# 测试正常转账（张三给李四转200元）
transfer_money(from_id=1, to_id=2, amount=200.00)

def batch_insert_users(users):
    """批量插入用户，使用事务保证全部成功/失败"""
    connection = None
    try:
        connection = mysql.connector.connect(
            host='localhost',
            user='root',
            password='123456',
            database='test_db'
        )
        connection.autocommit = False
        cursor = connection.cursor()
        insert_sql = "INSERT INTO user (name, age) VALUES (%s, %s)"
        # 批量执行SQL（效率更高）
        cursor.executemany(insert_sql, users)
        connection.commit()
        print(f"批量插入 {cursor.rowcount} 条数据成功")
    except Error as e:
        if connection:
            connection.rollback()
        print(f"批量插入失败，事务回滚：{e}")
    finally:
        if connection and connection.is_connected():
            cursor.close()
            connection.autocommit = True
            connection.close()
# 测试批量插入
user_list = [("王五", 30), ("赵六", 28), ("孙七", 35)]
batch_insert_users(user_list)