How to insert values into database the right way? - php

Question

For the last 5 hours I've been trying to figure out why this form won't insert data into MySQL when it seems to be correct.
Form
<form action="insertComment.php" method="POST">
<input type="hidden" name="article_id" value="<?php echo $article_uid;?>">
<input type="text" name="name" placeholder="Enter your name" required/>
<input type="email" name="email" placeholder="Enter your email" required/>
<textarea type="text" name="comment" placeholder="Join the discussion..." required></textarea>
<input type="submit" class="submit" value="Submit Comment"/>
</form>
then on comment.php
include '../../../libraries/phpClass/commentClass.php';
$commentClass = new commentClass();
if(isset($_POST['name']) AND isset($_POST['email']) AND isset($_POST['comment']) AND isset($_POST['article_id']))
{
$name = $_POST['name'];
$email = $_POST['email'];
$comment = $_POST['comment'];
$article_id = $_POST['article_id'];
$data = $commentClass->insertComment($name, $email, $comment, $article_id);
}
and this is the public function..
public function insertComment($name, $email, $comment, $article_id)
{
$sth = $this->db->prepare("INSERT INTO articles_comment(name, email, comment, article_id) VALUES (:name, :email, :comment, :article_id)");
$sth->execute(array(
':name' => $name,
':email' => $email,
':comment' => $comment,
':article_id' => $article_id
));
}
from what I can see there isn't anything wrong and I haven't been able to see anything why it wouldn't insert the values.. there are no errors whatsoever either..