codice:
$conn = new mysqli("localhost", "root", "", "tuodatabase");
if ($conn->connect_error) {
    echo $conn->connect_error;
    die;
}

$sql = "select * from app_event_book";
$result = $conn->query($sql);

while ($data = $result->fetch_array(MYSQLI_ASSOC)) {
    $dati[] = $data;
}

foreach ($dati as $field) {
    echo nl2br($field['n'] . " - " . $field['nome'] . " - " . $field['cognome'] . PHP_EOL);
}