Hey guy , while reading the book i got stuck on one place , i dont know what is the problem in my code , when i hit the delete button it deletes the jokes and the author from the db but it doens't delete the relations from jokecategory , this is my code:

Code:
<?php include $_SERVER['DOCUMENT_ROOT'] . '/training/preparations.php';
include $_SERVER['DOCUMENT_ROOT'].'training/funkcii/includes/functions.php';


try
{
$result = $pdo->query('SELECT id, name FROM author');
}
catch (PDOException $e)
{
$error = 'Error fetching authors from the database!';
include 'error.html.php';
exit();
}
foreach ($result as $row)
{
$authors[] = array('id' => $row['id'], 'name' => $row['name']);
}
include 'author.html.php';

if (isset($_POST['action']) and $_POST['action'] == 'Delete') {
	try
		{ 
		$sql = 'SELECT id FROM joke WHERE authorid = :id';
		$s = $pdo->prepare($sql);
		$s->bindValue (':id',$_POST['id']);
		$s->execute();
		}
	catch (PDOException $e)
	{
		$error = 'Error fetching the jokes to delete'.$e->getMessage();
		echo $error;
		exit();
	}
	$result = $s->fetchAll();
	try {
		$sql = 'DELETE FROM jokecategory WHERE jokeid = :id';
		$s = $pdo->prepare($sql);
	
		foreach ($result as $row)
			{
			$jokeId = $row['id'];
			$s->bindValue(':id', $jokeId);
			$s->execute();
			}
		}
	catch (PDOException $e)
	{
		$error = 'Error deleting category entryes for joke'.$e->getMessage();
		echo $error;
		exit();
	}
	try {
		$sql = 'DELETE FROM joke WHERE authorid = :id';
		$s = $pdo->prepare($sql);
		$s->bindValue(':id',$_POST['id']);
		$s->execute();
	}
	catch (PDOException $e)
	{
		echo 'Error deleting jokes from this author'.$e->getMessage();
		exit();
	}
	try 
	{
		$sql = 'DELETE FROM author WHERE id = :id';
		$s = $pdo->prepare($sql);
		$s->bindValue(':id',$_POST['id']);
		$s->execute();
	}
	catch (PDOException $e)
	{
		echo 'Error deleting the author'.$e->getMessage();
		exit();
	}
	header('Location: .');
	exit();
}

?>
author.html.php

Code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Manage Authors</title>
<link rel="stylesheet" type="text/css" href="../../css/style.css" />
</head>
<body>
<h1>Manage Authors</h1>
<p><a href="">Add new author</a></p>
<ul>
<?php foreach ($authors as $author): ?>
<li>
<form action="" method="post">
<div>
<?php htmlout($author['name']); ?>
<input type="hidden" name="id" value="<?php
echo $author['id']; ?>">
<input type="submit" name="action" value="Edit">
<input type="submit" name="action" value="Delete">
</div>
</form>
</li>
<?php endforeach; ?>
</ul>
<p><a href="..">Return to JMS home</a></p>
</body>
</html>