How to create a download link of files in databse - php

Question

I have created a upload form and a php file which extract the name, size, type of the file and stores it in a database upload script, in table files. The file is also given a uniqid which is also stored in the same table.
Now I am trying to build up a download.php file where I want that when a specific link with the uniqid in is opened the script look in databse for the file searching for the uniqid and show the information against it.?
Here is my upload.php
<?php
include('config.php');
function bytesToSize1024($bytes, $precision = 300) {
$unit = array('B','KB','MB');
return #round($bytes / pow(1024, ($i = floor(log($bytes, 1024)))), $precision).' '.$unit[$i];
}
$FileName = $_FILES['filename']['name'];
$FileType = $_FILES['filename']['type'];
$FileSize = bytesToSize1024($_FILES['filename']['size'], 1);
$Fileid = uniqid(rand());
$tmp_name = $_FILES["filename"]["tmp_name"];
if ($_FILES["filename"]["error"] > 0)
{
echo "Apologies, an error has occurred.";
echo "Error Code: " . $_FILES["fileToUpload"]["error"];
}
else
{
move_uploaded_file($_FILES["filename"]["tmp_name"],
"C:\wamp\www\upload\upload" . $_FILES["filename"]["name"]);
}
$query2 = "INSERT INTO files (id, name, size, type) VALUES ('$Fileid', '$FileName', '$FileSize', '$FileType')";
$result2 = mysql_query($query2);
echo <<<EOF
<p>Your file: {$FileName} has been successfully received.</p>
<p>Type: {$FileType}</p>
<p>Size: {$FileSize}</p>
<p>Temp Foler: {$tmp_name}</p>
<p>Download Link: localhost/upload/download.php?=$Fileid
EOF;
?>
Please first tell me which kind of link I should create like. localhost/download.php?=uniqid
will the above example work and how to make it work. I am confused?
Here I have tried to create a download.php file but it is not good
<?php
include('config.php');
$query = "SELECT * FROM files";
$result = mysql_query($query);
$row = mysql_fetch_array($result);
?>
<?php
echo <<<EOF
File Name: <?php echo $row['name']; ?>
$row
EOF;
?>

Answer 1

This is the code you need. Consider storing byte count in the database for file size.
Of course it might need some changes to be exactly what you want.
<?php
include('config.php');
//get id from GET method and make sure that it's safe to be used in the query
$id=mysql_real_escape_string($_GET['id']);
$query = "SELECT * FROM `files` WHERE `id`='$id'";
$result = mysql_query($query);
$row = mysql_fetch_array($result);
if (count($row)!=1) //check if our unique record has been found
die('Sorry but we could not find this file!');
$row=$row[0];
//send download headers
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.$row['name']);
header('Content-Transfer-Encoding: binary');
header('Cache-Control: must-revalidate');
header('Pragma: no-cache');
header('Content-Length: ' .$row['size']);
readfile(upload" . $row['name']); //I recommend you to change the path and file name of your uploaded files!
?>
Link example: http://yourdomain.com/download.php?id=123