@Celko; şu örnek işinize yarayabilir.

Bilgisayarınızda veya sunucunuzda Composer kurulu değilse şu yazımı okumanızı tavsiye ediyorum.

composer.json;

{
	"minimum-stability": "dev",
	"require": {
		"imsaintx/utils": "dev-master",
		"phpoffice/phpexcel": "dev-master"
	}
}

app.php;

<?php
	
	error_reporting(E_ALL);
	
	ini_set("display_errors", true);
	ini_set("display_startup_errors", true);
	ini_set("html_errors", false);
	
	set_include_path(str_replace("\\", "/", dirname(realpath(__FILE__))));
	
	date_default_timezone_get("Europe/Istanbul");
	
	function path($file)
	{
		return get_include_path()."/".$file;
	}
	
	function load($file)
	{
		require(get_include_path()."/{$file}");
	}
	
	load("vendor/autoload.php");
	
	use \Tools\Utils;
	
	Utils::utf8_header("text/plain");
	
	define("DB_HOST", "127.0.0.1");
	
	define("DB_PORT", 3306);
	
	define("DB_USER", ""); # MySQL kullanıcı adı
	
	define("DB_PASS", ""); # MySQL şifre
	
	define("DB_NAME", ""); # MySQL veritabanı ismi
	
	define("DB_CHARSET", "utf8");
	
	define("DB_COLLATE", "utf8_general_ci");
	
	$mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME, DB_PORT);
	
	$mysqli->set_charset(DB_CHARSET);
	
	$mysqli->query(
		sprintf("SET NAMES %s;", DB_CHARSET).
		sprintf("SET NAMES %s COLLATE %s;", DB_CHARSET, DB_COLLATE).
		sprintf("SET character_set_client = %s;", DB_CHARSET).
		sprintf("SET character_set_results = %s;", DB_CHARSET).
		sprintf("SET character_set_connection = %s;", DB_CHARSET).
		sprintf("SET collation_connection = %s;", DB_COLLATE)
	);
	
	$objPHPExcel = new PHPExcel();
	
	$objPHPExcel->getProperties()->setCreator("Ogün Karakuş")->setlastModifiedBy("Ogün Karakuş")->setTitle("Test Document");
	
	$query = $mysqli->query("SELECT * FROM `TABLO_İSMİ`"); # MySQL sorgusu
	
	$fields = $query->fetch_fields();
	
	$alphabet = range("A", "Z");
	
	foreach($fields as $key => $value)
	{
		$cell = $alphabet[$key] . "1";
		
		$objPHPExcel->setActiveSheetIndex(0)->setCellValue($cell, $value->name);
		
		$objPHPExcel->getActiveSheet()->getColumnDimension($alphabet[$key])->setWidth(12);
	}
	
	$rows = array();
	
	while($row = $query->fetch_assoc())
	{
		$rows[] = $row;
	}
	
	foreach($rows as $key => $value)
	{
		$values = array_values($value);
		
		foreach($values as $key2 => $value2)
		{
			$cell = $alphabet[$key2];
			$cell .= (string) $key + 2;
			
			$objPHPExcel->setActiveSheetIndex(0)->setCellValue($cell, $value2);
		}
	}
	
	$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, "Excel2007");
	
	$objWriter->save(path("test-document.xlsx"));
	
	$mysqli->close();
	
	echo "test-document.xlsx olarak kaydedildi.";