Using the PHPSpreadsheet Exporter:

PHPSpreadsheet also provides an exporter class that simplifies the process of exporting database data to Excel. Here's an example:

//...

require 'vendor/autoload.php';

use PhpOffice\PhpSpreadsheet\IOFactory;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

// Connect to the database
$dsn = 'mysql:host=localhost;dbname=test';
$username = 'username';
$password = 'password';

$pdo = new PDO($dsn, $username, $password);

// Fetch data from the database
$query = 'SELECT * FROM users';
$stmt = $pdo->query($query);
$data = $stmt->fetchAll(PDO::FETCH_ASSOC);

// Create a new spreadsheet
$spreadsheet = IOFactory::load('template.xlsx');

// Add the data to the spreadsheet
$sheet = $spreadsheet->getActiveSheet();
$sheet->fromArray($data, null, 'A2');

// Save the spreadsheet to a file
$writer = new Xlsx($spreadsheet);
$writer->save('users.xlsx');

//...

In this example, we first require the PhpSpreadsheet library. We establish a database connection using `PDO`. We fetch the data from the database using a query and store it in the `$data` variable. We load a template spreadsheet using `IOFactory::load()`. We get the active sheet and add the data to the spreadsheet using `$sheet->fromArray()`. Finally, we save the spreadsheet to an Excel file using the `Xlsx` writer and the `save()` method.



These examples demonstrate techniques for exporting database data to Excel using PHP 8 and the PhpSpreadsheet library. You can customize the data retrieval and export process based on your database structure and requirements. Experiment with these examples and integrate them into your web applications to efficiently export database data to Excel files.