php export excel

composer require phpoffice/phpspreadsheet

$books = [
    ['ISBN', 'title', 'author', 'publisher', 'ctry' ],
    [618260307, 'The Hobbit', 'J. R. R. Tolkien', 'Houghton Mifflin', 'USA'],
    [908606664, 'Slinky Malinki', 'Lynley Dodd', 'Mallinson Rendel', 'NZ']
];
$xlsx = SimpleXLSXGen::fromArray( $books );
$xlsx->saveAs('books.xlsx');
//  $xlsx->downloadAs('books.xlsx');
//git repo given below 

$queryexport = ("
SELECT username,password,fullname FROM ecustomer_users
WHERE fk_customer='".$fk_customer."'
");

$row = mysql_fetch_assoc($queryexport);

$result = mysql_query($queryexport);
$header = '';

for ($i = 0; $i < $count; $i++){
   $header .= mysql_field_name($result, $i)."\t";
   }

while($row = mysql_fetch_row($result)){
   $line = '';
   foreach($row as $value){
          if(!isset($value) || $value == ""){
                 $value = "\t";
          }else{
                 $value = str_replace('"', '""', $value);
                 $value = '"' . $value . '"' . "\t";
                 }
          $line .= $value;
          }
   $data .= trim($line)."\n";
   $data = str_replace("\r", "", $data);

if ($data == "") {
   $data = "\nno matching records found\n";
   }
}
header("Content-type: application/vnd.ms-excel; name='excel'");
header("Content-Disposition: attachment; filename=exportfile.xls");
header("Pragma: no-cache");
header("Expires: 0");

// output data
echo $header."\n".$data;

mysql_close($conn);`