lib_db.php

<?php

DEFINE("DB_ADDRESS", "localhost");
DEFINE("DB_NAME", "#####");
DEFINE("DB_USER", "#####");
DEFINE("DB_PASSWORD", "#####");

function openConnection(){
    // Create connection
    $conn = new mysqli(DB_ADDRESS, DB_USER, DB_PASSWORD, DB_NAME);

    // Check connection
    if ($conn->connect_error) {
        die("Connection failed: " . $conn->connect_error);
    }
    echo "Connected successfully\n";

    return $conn;
}

function closeConnection($conn){
    $conn->close();
}

function saveMessage($conn, $message) {
    $conn->query("INSERT INTO message (id, payload) VALUES (NULL, '$message')")
        or die(mysqli_error($conn));
}


function getMessageCount($conn) {

    $count = 0;

    if($result = $conn->query("SELECT COUNT(*) as count FROM message")) {
        $array_result = $result->fetch_assoc();
        printf("Totale messaggi: %d\n", $array_result['count']);
        $count = $array_result['count'];
    }

    $result->close();

    return $count;
}