Ho creato questo db con php, ma quando clicco su invia non mi aggiunge il record, sulla tabella
Codice PHP:
<html><head><title>Inserimento Dati</title></head><body><table><tr><td>INSERIMENTO DATI</td></tr><tr><td>Firstname</td><td><input type="firstname"><tr><tr></td><td>Lastname</td><td><input type="lastname"></td><tr><tr><td>Email</td><td><input type="email"></td></tr><tr><td><form action="insert.php" method="POST"><input type="submit"></input></form></td></tr></table></body></html> 
Codice PHP:
<?php
?><table border="1" align="center"><tr><td align="center">firstname</td><td align="center">lastname</td><td align="center">email</td></tr><?php$servername = "localhost";$username = "root";$password = "";$dbname = "my_db";
// Create connection$conn = new mysqli($servername, $username, $password, $dbname);// Check connectionif (isset($conn->connect_error)) {    die("Connection failed: " . $conn->connect_error);} 
$sql = "INSERT INTO Mytable (firstname, lastname, email)VALUES ('John', 'Doe','john@example.com')";
if ($conn->query($sql) === TRUE) {    echo "New record created successfully";} else {    echo "Error: " . $sql . "<br>" . $conn->error;}
$conn->close();?><?php$db_connection= mysql_connect($servername, $username, $password, $dbname);$db_selection = mysql_select_db('my_db',$db_connection);
$query = mysql_query("SELECT distinct firstname, lastname, email FROM Mytable WHERE id ");while($foreach = mysql_fetch_array($query)){ 
    echo "     <tr>    <td>".$foreach['firstname']."</td><td>".$foreach['lastname']."</td><td>".$foreach['email']."</td>    </tr>";    }    ?></table>