<?php
$servername = "localhost";
$username = "root";
$password = "root";

$query = "SELECT A.ssn, COUNT( A.albumidentifier ) AS TotMax
    FROM albumproducer AS A
    GROUP BY A.ssn
    HAVING COUNT( A.albumidentifier )=(SELECT MAX(D.Tot1) FROM (
    SELECT COUNT( B.albumidentifier ) AS Tot1
    FROM albumproducer AS B
    GROUP BY B.ssn
    ) AS D)";

$conn = new mysqli($servername, $username, $password);

if ($conn->connect_error) {
    die("Connessione fallita: " . $conn->connect_error);
    }
echo "Connessione avvenuta con successo <br>";

    echo "<br><b>(Richiesta inviata: )</b><br>";
    echo $query;
?>;