<?php
include "db.php";

function showAllData(){
    global $connection;
    $query = "SELECT * FROM users";
    $result = mysqli_query($connection, $query);
    if(!$result){
        die('Query Failed' . mysqli_error());
    }

  while($row = mysqli_fetch_assoc($result)){

          $id = $row['id'];

         echo  "<option value='$id'>$id</option>";

       }
}

function UpdateTable(){

    global $connection;
   $username = $_POST['username'];
   $password = $_POST['password'];
    $id = $_POST['id'];
$query = "UPDATE users SET ";
$query .= "username = '$username', ";
$query .= "password = '$password' ";
$query .= "WHERE id = $id ";
    $result = mysqli_query($connection, $query);
         if(!$result){
             die("QUERY FAILED" . mysqli_error($connection));
         }
}

function deleteRows(){

    global $connection;
   $username = $_POST['username'];
   $password = $_POST['password'];
    $id = $_POST['id'];

    $query = "DELETE FROM users";
$query .= "WHERE id = $id ";

    $result = mysqli_query($connection, $query);
         if(!$result){
             die("QUERY FAILED");
         }
}