<?php
session_start();

$host = "ip:port";
$user = "root";
$password = "admin";
$db = "segnalazioni";
$conn = mysqli_connect($host, $user, $password, $db);
$errore = "Tentativo di accesso non valido";
$errorNoUsername = "Inserire i dati per loggare";

if(isset($_POST['username'])){
    $userUsername = $_POST['username'];
    $userPassword = $_POST['password'];
    $sql = "SELECT * FROM utenti WHERE username='".$userUsername."' AND password = '".$userPassword."'";
    $result = mysqli_query($conn, $sql);

    if(mysqli_num_rows($result)==1){
        $_SESSION['username'] = $userUsername;
        header('location: main.php');
    } else {
        echo $errore;
    }
} else {
    echo $errorNoUsername;
}
?>