AJAX - Request MySQL data through PHP

Suppose we need to get password (actually hash value in database) of a specified user, how we can make that?

We have a form to get user name input and have a button associated with function getResult().

 


    Admin Name
    


    

getResult()

function getResult() {
    var xmlhttp = new XMLHttpRequest();
    var name = document.getElementById("name").value;
    xmlhttp.onreadystatechange = function() {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            setTimeout(function() {document.getElementById("result").innerHTML = xmlhttp.responseText;}, 1000);
        } else {
            document.getElementById("result").innerHTML = "Loading...";
        }
    }
   
    xmlhttp.open("POST", "getuserhash.php");
    xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xmlhttp.send("name=" + name);
}

getuserhash.php

include_once('connection.php');

$name = $_POST['name'];

$query = $pdo->prepare("SELECT user_password FROM user WHERE user_name = ?");
$query->bindValue(1, $name);
$query->execute();
$data = $query->fetch();

echo $data["user_password"];

It works!

Use jQuery to rewrite getResult()

        
function getResult() {
    var name = $("#name").val();
    $.post("getuserhash.php", {name:name}, 
        function(data) {
            $("#result").html(data);
        }
    );
}