"$.get(url, function (data, status){ alert(data); }" not working on mysqli - php

Question

<script type="text/javascript">
function signup() {
var url = "process/sign-up-process.php?" + $("#signup-form").serialize();
// alert(url);
$.get(url, function (data, status) {
alert(data);
});
}
</script>
Page: process/sign-up-process.php code goes below
<?php
require_once('connection.php');
$full_name = filter_input(INPUT_GET, 'full_name', FILTER_SANITIZE_STRING);
$email = $_GET['email'];
$email = filter_var($email, FILTER_VALIDATE_EMAIL);
$user_password = filter_input(INPUT_GET, 'user_password', FILTER_SANITIZE_STRING);
$query = "INSERT INTO registered_users_list (full_name, email, user_password) VALUES ('$full_name', '$email', '$user_password')";
$query1 = mysqli_query($conn, $query);
$count = mysqli_affected_rows($conn);
if($count == 1){
echo "Signed up";
}else{
echo "Sorry";
}
?>
The problem is in "process/sign-up-process.php" page, when I comment out the query code and
echo "Some Random Text"
then the
alert(data)
works. But when I tried to run INSERT query it doesn't work. I think the error must be in PHP improved i.e mysqli string.

Answer 1

I can bet $10 that the page you are requesting returns an error instead of text. In chrome, before sending the AJAX request press F12 and go to Network tab. Click on the () Clear sign to clear all entries if needed. Then when the ajax call proceeds check out the response. It's most probably a mysqli error page (Chrome dev console screenshot: http://image.prntscr.com/image/84e59bfb9caf4c9b9dcf8b5f79844176.png )
Probably even better: Request Monitoring in Chrome
A great tutorial if you don't know what I am talking about: https://www.youtube.com/watch?v=AXGB4tIRNgM