可下载的csv文件

<?php
require_once 'config.php';
require_once 'mysql.func.php';
$link = connect($host,$username,$password,$dbName,$charset);
$sql = "select * from tbl_tag";
$data = getAll($sql);
$output = fopen("php://output",'w') or die("can't open php://output");
header('Content-Type:application/csv');
header('Content-Disposition:attachment;filename="file.csv"');
fputcsv($output,array('id','name','frequency'));

foreach($data as $data_line){
fputcsv($output,$data_line);
}
fclose($output) or die("Can't close output");
?>