FORM POST 2

<?php
/*
phpinfo();
exit();
*/

class Applicativo {
    const HOST = 'localhost';
    const USERNAME = '//';
    const PASSWORD = '//';
    const DATABASE = '//';

    public $dbo;

    public function __constructor(){
        try{
            $this->dbo = new mysqli(self::HOST, self::USERNAME, self::PASSWORD, self::DATABASE);

        } catch (\Exception $e) {
            echo $e->getMessage();
            exit();
        }
    }

    public function save($dati){
        $nome = $dati['nome'];
        $cognome = $dati['cognome'];
        $data = $dati['data'];
        $password_cript = md5($dati['password']);
        $cellulare = $dati['cellulare'];

        try{
        $query = "INSERT INTO utenti
            (nome, cognome, password, cellulare)
            VALUES
            ('".$nome."','".$cognome."','".$password_cript."','".$cellulare."');
            ";
        $result = $this->dbo->query($query);
        } catch (\Exception $e) {
            echo $e->getMessage();
            exit();
        }

        if(!$result){
            die('Errore query: '.$query);
        }else{
            echo 'Query eseguita con successo';
        }
    }

}

if(isset($_POST['invia'])){
    $registrazione = new Applicativo();
    $registrazione->save($_POST);
}else{
?>

<form method="POST" action="#">
<input type="text" name="nome" placeholder="Nome">
<input type="text" name="nome" placeholder="Cognome">
<input type="password" name="password" placeholder="Password">
<input type="date" name="data" placeholder="Nascita (aaaa-mm-gg)">
<input type="submit" name="invia" value="invia">
</form>

<?php
}
?>