如何利用PHP编写员工考勤数据的自动生成报表？

CREATE TABLE `attendance` (
  `id` INT(11) NOT NULL AUTO_INCREMENT,
  `employee_name` VARCHAR(50) NOT NULL,
  `department` VARCHAR(50) NOT NULL,
  `attendance_date` DATE NOT NULL,
  `start_time` TIME NOT NULL,
  `end_time` TIME NOT NULL,
  PRIMARY KEY (`id`)
);

// 数据库连接配置
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

// 创建数据库连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("数据库连接失败: " . $conn->connect_error);
}

// 查询考勤数据的SQL语句
$sql = "SELECT * FROM attendance";

// 执行查询
$result = $conn->query($sql);

// 检查查询结果是否为空
if ($result->num_rows > 0) {
    // 初始化一个空数组来保存查询结果
    $attendanceData = array();

    // 将每行数据添加到数组中
    while ($row = $result->fetch_assoc()) {
        // 将数据添加到数组中
        $attendanceData[] = $row;
    }
} else {
    echo "没有找到考勤数据";
}

// 引入PHPExcel库
require_once 'PHPExcel.php';

// 创建一个新的Excel对象
$objPHPExcel = new PHPExcel();

// 设置当前活动的工作表
$objPHPExcel->setActiveSheetIndex(0);

// 标题行
$objPHPExcel->getActiveSheet()->setCellValue('A1', '员工姓名');
$objPHPExcel->getActiveSheet()->setCellValue('B1', '部门');
$objPHPExcel->getActiveSheet()->setCellValue('C1', '考勤日期');
$objPHPExcel->getActiveSheet()->setCellValue('D1', '上班时间');
$objPHPExcel->getActiveSheet()->setCellValue('E1', '下班时间');

// 填充数据行
$row = 2;
foreach ($attendanceData as $data) {
    $objPHPExcel->getActiveSheet()->setCellValue('A'.$row, $data['employee_name']);
    $objPHPExcel->getActiveSheet()->setCellValue('B'.$row, $data['department']);
    $objPHPExcel->getActiveSheet()->setCellValue('C'.$row, $data['attendance_date']);
    $objPHPExcel->getActiveSheet()->setCellValue('D'.$row, $data['start_time']);
    $objPHPExcel->getActiveSheet()->setCellValue('E'.$row, $data['end_time']);
    $row++;
}

// 保存Excel文件
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
$objWriter->save('attendance_report.xls');

echo "考勤报表已生成";