php mysqli事务

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 开启事务
$conn->begin_transaction();

try {
    // 执行SQL语句
    $sql1 = "UPDATE accounts SET balance = balance - 100 WHERE id = 1";
    $sql2 = "UPDATE accounts SET balance = balance + 100 WHERE id = 2";

    if ($conn->query($sql1) === TRUE && $conn->query($sql2) === TRUE) {
        // 提交事务
        $conn->commit();
        echo "转账成功";
    } else {
        // 回滚事务
        $conn->rollback();
        echo "转账失败";
    }
} catch (Exception $e) {
    // 发生异常时回滚事务
    $conn->rollback();
    echo "发生异常: " . $e->getMessage();
}

// 关闭连接
$conn->close();
?>