Failed to replace PDF in database with another PDF using PHP - php

Question

I am trying to replace one pdf that previously upload in MySQL to another pdf . I created an a href [edit] for user to choose the pdf file and link to editDB.php where query update placed.
This is edit.DB.php
<?php
// Connect to the database
$host="localhost"; // Host name
$username="root"; // Mysql username
$password=""; // Mysql password
$db_name="is"; // Database name
$tbl_name="publication"; // Table name
if(isset($_POST['submit']) && $_FILES['userfile']['size'] > 0)
{
$fileName = $_FILES['userfile']['name'];
$tmpName = $_FILES['userfile']['tmp_name'];
$fileSize = $_FILES['userfile']['size'];
$fileType = $_FILES['userfile']['type'];
$fp = fopen($tmpName, 'r');
$content = fread($fp, filesize($tmpName));
$content = addslashes($content);
fclose($fp);
if(!get_magic_quotes_gpc())
{
$fileName = addslashes($fileName);
}
$conn = mysql_connect("$host", "$username", "$password");
if(! $conn )
{
die('Could not connect: ' . mysql_error());
}
Connect database, fetch file_id, fetch other data that updated
$conn = mysql_connect("$host", "$username", "$password");
if(! $conn )
{
die('Could not connect: ' . mysql_error());
}
if (isset($_GET["id"]))
{
$id =$_GET["id"];
}
else
{
echo'failed';
}
mysql_select_db($db_name);
$title=mysql_real_escape_string($_POST['title']);
$author=mysql_real_escape_string($_POST['author']);
$year=mysql_real_escape_string($_POST['year']);
$abs=mysql_real_escape_string($_POST['abstract']);
query here
$query="update publication set title='".$title."', author='".$author."', year='".$year."' , abstract='".$abs."', file_name='".$fileName."', file_size='".$fileSize."', file_type='".$fileType."', content='".$content."' where file_id='$id'";
mysql_query($query) or die(mysql_error());
echo '<script type="text/javascript">alert("'.$title.' updated!");
window.location.href="publication.php";
</script>';
mysql_close($conn);
}
?>
The problem I faced is that , after I key in updated info in my edit form. The data successfully direct to editDB.php. pop up dialog showing data updated is shown but the data did not updated both database and the page showing info. I will be grateful for any help hands. Thanks.

Answer 1

Instead of
if (isset($_GET["id"]))
{
$id =$_GET["id"];
}
else
{
echo'failed';
}
i change it to
if(isset($_POST['submit'])&& $_FILES['userfile']['size'] > 0)
{
$id =$_POST["id"];
Of course the id must pass properly and make sure id is match with ur database.
This code can works. Hope able to help you all.