PHP를 통해 직원 출석 데이터를 정기적으로 동기화하는 방법은 무엇입니까?

CREATE TABLE `attendance` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` int(11) NOT NULL,
  `date` date NOT NULL,
  `clock_in` time DEFAULT NULL,
  `clock_out` time DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

<?php

// 连接源数据库
$source_db_host = 'localhost';
$source_db_user = 'username';
$source_db_pass = 'password';
$source_db_name = 'source_db';
$source_db = mysqli_connect($source_db_host, $source_db_user, $source_db_pass, $source_db_name);

if (!$source_db) {
    die('源数据库连接失败: ' . mysqli_connect_error());
}

// 连接目标数据库
$target_db_host = 'localhost';
$target_db_user = 'username';
$target_db_pass = 'password';
$target_db_name = 'target_db';
$target_db = mysqli_connect($target_db_host, $target_db_user, $target_db_pass, $target_db_name);

if (!$target_db) {
    die('目标数据库连接失败: ' . mysqli_connect_error());
}

// 获取源数据库中的员工考勤数据
$sql = "SELECT * FROM employee_attendance";
$result = mysqli_query($source_db, $sql);

if (!$result) {
    die('查询失败: ' . mysqli_error($source_db));
}

// 将数据插入到目标数据库中
while ($row = mysqli_fetch_assoc($result)) {
    $user_id = $row['user_id'];
    $date = $row['date'];
    $clock_in = $row['clock_in'];
    $clock_out = $row['clock_out'];

    $sql = "INSERT INTO attendance (user_id, date, clock_in, clock_out) VALUES ('$user_id', '$date', '$clock_in', '$clock_out')";
    $result = mysqli_query($target_db, $sql);

    if (!$result) {
        die('插入数据失败: ' . mysqli_error($target_db));
    }
}

// 关闭数据库连接
mysqli_close($source_db);
mysqli_close($target_db);

echo "数据同步完成！";

crontab -e

0 2 * * * php /path/to/sync_attendance.php