<?php
   $db_host="localhost";
   $db_user="root";
   $db_pass="";
   $db_name="enr";

   $db = new mysqli($db_host, $db_user, $db_pass, $db_name);

    if($db->connect_error){
       die("Connection failed: " . $db->connect_error);
   }
?>

<?php

include ("config.php");

$id = "";
$image = "";
$name = "";
$reg ="";
$contact = "";
$email = "";
$shift = "";
$semester = "";
$courses = "";

if (isset($_POST["update"]))
{
    $query = "UPDATE students
            SET  image = '$image', name = '$name', reg = '$reg', contact = '$contact', email = '$email', shift = '$shift',semester ='$semester', courses = '$courses'
            WHERE id = '$id' ";
    try{
        $data = mysqli_query($db, $query);
        if($data)
        {
            if(mysqli_affected_rows($db) > 0)
            {
                echo '<div id="msg"> Data Updated <a href="display.php">Check Data</a> </div>';
            }else{
                echo '<div id="msg"> Data could not be updated <a href="display.php">Check Data</a> </div>';
            }
        }
    } catch (Exception $ex) {
        echo 'Error Update '.$ex->getMessage();
    }
}
?>