How to update record by getting id from Url

How to update record by getting. id from Url
Following steps are required

1. your url should contain id that you can add by using ? after address like test.php?
2.For getting id you have get id by making variable $id=$_GET[id];
3.In update query you have to write this
$que="UPDATE admin SET image =  '$file_name' WHERE  id ='$id'";
4.when you are getting the id from update url make sure that your form action should echo id in url like this
<form action="test.php?id=<?php echo $id ?>" >
5.its simple and easiest way to get id from url and update id