Exporter une base de données dans excel

 <div class="box-body">
                  <div class="table-responsive">
					<label> Fichier NAs :</label>
					<center>
						<i class="fa fa-download"></i>
						<a id="liennotajax" href="fichier/NAs.xlsx" rel="nofollow noopener noreferrer" target="_blank" download="NRAs.xlsx"> télécharger</a>
					</center>
                  </div>

function array_to_csv_download($array, $filename = "export.csv", $delimiter=";") {
    header('Content-Type: application/csv');
    header('Content-Disposition: attachment; filename="'.$filename.'";');

    // open the "output" stream
    // see http://www.php.net/manual/en/wrappers.php.php#refsect2-wrappers.php-unknown-unknown-unknown-descriptioq
    $f = fopen('php://output', 'w');

    foreach ($array as $line) {
        fputcsv($f, $line, $delimiter);
    }
} 

$arr_datas = array( array(1,2,3,4),  array(1,2,3,4));
array_to_csv_download($arr_datas,  "monfichier.csv");

<?php
	require('../../bd_connect.php');

function cleanData(&$str)
  {
    // escape tab characters
    $str = preg_replace("/\t/", "\\t", $str);

    // escape new lines
    $str = preg_replace("/\r?\n/", "\\n", $str);

    // convert 't' and 'f' to boolean values
    if($str == 't') $str = 'TRUE';
    if($str == 'f') $str = 'FALSE';

    // force certain number/date formats to be imported as strings
    if(preg_match("/^0/", $str) || preg_match("/^\+?\d{8,}$/", $str) || preg_match("/^\d{4}.\d{1,2}.\d{1,2}/", $str)) {
      $str = "'$str";
    }

    // escape fields that include double quotes
    if(strstr($str, '"')) $str = '"' . str_replace('"', '""', $str) . '"';
  }

  // filename for download
  $filename = "Expordata" . date('Ymd') . ".xls";

  header("Content-Disposition: attachment; filename=\"$filename\"");
  header("Content-Type: application/vnd.ms-excel");

  $flag = false;
  $requete = "SELECT informations // je les ai effacés " or die('Query failed!');
  $resultats= $bdd_connection->query($requete);
  while($row = $resultats->fetch()){
    if(!$flag) {
      // display field/column names as first row
      echo implode("\t", array_keys($row)) . "\r\n";
      $flag = true;
    }
    array_walk($row, __NAMESPACE__ . '\cleanData');
    echo implode("\t", array_values($row)) . "\r\n";
  }
  exit;
?>