The code is for downloading excel file(.xls) - php

Question

Problem:
After download, the file doesn't contain the data.
i.e it become blank.
So please help me for this.
<?php
session_start();
include_once 'oesdb.php';
$id=$_REQUEST['id'];
if(isset($_REQUEST['id']))
{
$sql=executeQuery("SELECT * FROM file where id=$id");
$rows = mysql_fetch_array($sql);
$file =$rows['file'];
header('Content-Description: File Transfer');
header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment; filename='.basename($file));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
ob_clean();
flush();
readfile('uploads/'.$file);
exit;
}
?>

Answer 1

Why not create a HTACCESS file in uploads folder then states
Allow From 127.0.0.1
Deny From All
Then just create a URL, use HTML5's new download feature, do something like this:
click to download
It saves time trying to use PHP to make a download script.

Answer 2

try replacing this:
$file =$rows['file'];
by this:
$file = "uploads/".$rows['file'];
and this:
readfile('uploads/'.$file);
by this
readfile($file);
if still not working put the value returned by the readfile function
IMPORTANT
Please take in consideration the sql injection issues (see comment of Ondřej Mirtes)

Answer 3

The problem is here:
header('Content-Length: ' . filesize($file));
Content-Length receives zero value and browser downloads zero-length file, as you told him. If $file is path relative to upload/, you should do this:
header('Content-Length: ' . filesize('upload/'.$file));
Be sure that filezise() returns correct size and readfile() realy outputs it.
But the other problem is that you mentioned UPLOAD folder and using uploads. They are not same and case is important. Also, may be using relative paths in 'uploads/'.$file is not a good idea, it is better to use absolute path. For example, '/var/www/upload/'.$file.