通过调用php页面的javascript Ajax将数据发布到数据库

Question

So basically I want to have a Javascript function that posts data to a table in my database. i know that I need to call a php page to do this. But the code I have written doesn't work. The js fucntion is triggered by a button press in html. I need to do this in js ajax and not jquery ajax

The Javascript

function comment_sub(){
 var xhttp = new XMLHttpRequest();
 xhttp.onreadystatechange = function() 
{
    if (this.readyState == 4 && this.status == 200) 
    {    
    }
};
xhttp.open("POST", "static/setcomments.php", true);
xhttp.send(encodeURIComponent(document.getElementById('comment-textbox').value));  
}

The PHP

<?php
echo "Hello";
$mydb = mysqli_connect("localhost", "root","", "website");
if (!$mydb){
    die("Connection failed".mysqli_connect_error());
}
$sql = "INSERT INTO 'comments'('comment_text') VALUES ('{$_GET['comment-textbox']}')";
$query = mysqli_query($mydb, $sql);
if (!$query)
{
  die('Error: ' . mysql_error());
}
echo "1 record added"
?>

Checked the network and console log. The JS function is being called fine but the network logs gives me a 404 error for the post request

Answer 1

You are only sending the value itself, not the name comment-textbox .

Try this:

xhttp.send(JSON.stringify({
    'comment-textbox': document.getElementById('comment-textbox').value
}));

Answer 2

On the PHP page, you are doing a HTTP POST and not a HTTP GET. So rewrite it as this:

$sql = "INSERT INTO 'comments'('comment_text') VALUES ('{$_POST['comment-textbox']}')";