How to add values to a mySQL database with JSON and AJAX? - php

Question

Currently blank rows are being entered into my mySQL database. Undefined index is what I'm getting for Name and Address in the PHP. I'm using the javaScript code as part of a function. The user will activate this function and this adding to the database will happen seemless behind the scenes.
How can I get the values to enter the mySQL.
PHP Code,
<?php
$connection = mysqli_connect("localhost", "user", "pass", "db");
$name = $_POST['Name'];
$address = $_POST['Address'];
mysqli_query($connection,"INSERT INTO offerSelected (Id, Url) VALUES ('".$name."','".$address."')");
?>
JavaScript
var name = "John";
var address = "UK";
var sendInfo = {
Name: name,
Address: address
};
var params = JSON.stringify(sendInfo);
alert(params);
var httpSend = new XMLHttpRequest();
var php = "http://server/~name/folder/insertOffer.php";
httpSend.open("POST", php, true);
httpSend.onreadystatechange = function()
{
if(httpSend.readyState == 4 && httpSend.status == 200) {
alert("sent");
}
}
httpSend.send(params);
UPDATED
var params = 'Name=' + name + '&Address=' + address;
alert(params);
var httpSend = new XMLHttpRequest();
var php = "http://server/~name/folder/insertOffer.php";
httpSend.open("POST", php, true);
httpSend.onreadystatechange = function()
{
if(httpSend.readyState == 4 && httpSend.status == 200) {
alert("h");
}
}
httpSend.send(params);

Answer 1

Apart from the SQL injection problems people mentioned in the comments, the problem with your code is JSON.stringify. The POST parameters use a key-value format just like GET requests, which means your params should look like this:
Name=name&Address=address
And not a JSON object. You also have to add this line of code after httpSend.open to tell the server that you are sending key/values:
httpSend.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");