insertintable

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "scuola";
$tabname = "studenti";
$nome = $_POST['nome'];
$cognome= $_POST['cognome'];
$matricola= $_POST['matricola'];
$classe= $_POST['classe'];
$ddn= $_POST['ddn'];
try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    // set the PDO error mode to exception
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $sql = "INSERT INTO $tabname (nome, cognome, matricola, classe, ddn)
    VALUES ('$nome', '$cognome', '$matricola', '$classe', '$ddn')";
    // use exec() because no results are returned
    $conn->exec($sql);
    echo "New record created successfully";
    }
catch(PDOException $e)
    {
    echo $sql . "<br>" . $e->getMessage();
    }
header("Location: creaStudenti.html");
$conn = null;
?>