Export a MySQL dataset to CSV using php://output stream and fputcsv

exportexample.php

<?php
header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment;filename="export.csv"');
header('Cache-Control: max-age=0');
// See: http://es2.php.net/manual/en/wrappers.php.php
$fpcsv = fopen('php://output', "a+");
// Put your SQL query here
$exportcsv_q = mysql_query($query);
if (@mysql_num_rows($exportcsv_q) > 0) {
    $campos = mysql_num_fields($exportcsv_q);
    while ($exportcsv_r = mysql_fetch_row($exportcsv_q)) {
         fputcsv($fpcsv, $exportcsv_r);
    }
}
exit;