PHP를 통해 직원 출석 데이터를 가져오고 내보내는 방법은 무엇입니까?

<form action="import.php" method="post" enctype="multipart/form-data">
    <input type="file" name="file" accept=".csv">
    <input type="submit" value="导入">
</form>

<?php
// 导入数据
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    // 获取上传的文件
    $file = $_FILES['file']['tmp_name'];
    
    // 连接数据库
    $conn = new mysqli('localhost', 'username', 'password', 'database_name');
    
    // 读取CSV文件
    if (($handle = fopen($file, "r")) !== false) {
        while (($data = fgetcsv($handle, 1000, ",")) !== false) {
            // 将数据插入数据库
            $sql = "INSERT INTO attendance (employee_id, date, start_time, end_time) 
                    VALUES ('$data[0]', '$data[1]', '$data[2]', '$data[3]')";
            $conn->query($sql);
        }
        fclose($handle);
    }
    
    // 关闭数据库连接
    $conn->close();
    
    // 导入成功提示
    echo "导入成功";
}
?>

<a href="export.php">导出</a>

<?php
// 导出数据
// 连接数据库
$conn = new mysqli('localhost', 'username', 'password', 'database_name');

// 查询员工考勤数据
$sql = "SELECT * FROM attendance";
$result = $conn->query($sql);

// 创建CSV文件
$file = fopen("attendance.csv", "w");

// 写入表头
fputcsv($file, array("员工ID", "日期", "上班时间", "下班时间"));

// 写入数据
while ($data = $result->fetch_assoc()) {
    fputcsv($file, array($data['employee_id'], $data['date'], $data['start_time'], $data['end_time']));
}

// 关闭文件
fclose($file);

// 关闭数据库连接
$conn->close();

// 下载CSV文件
header("Content-type: text/csv");
header("Content-Disposition: attachment; filename=attendance.csv");
readfile("attendance.csv");
?>