How can I change this code to show WHY an insert failed? PHP, MySQLi, Prepared Statements
$dbc = mysqli_connect(DB_HOST, DB_USER, DB_USER_PASSWORD, DB_NAME) or die(DB_CONNECT_ERROR);
    if (!$stmt = mysqli_prepare($dbc, $query)) die('SEL:mysqli_prepare');
    call_user_func_array('mysqli_stmt_bind_param', array_merge(array($stmt, 'sssssssssssssssssssssbsssss')), $idb);
    mysqli_stmt_execute($stmt);

    if (!mysqli_stmt_affected_rows($stmt)) {
            // Failed to insert
    } else {
            // Success
            }

mysqli_stmt_execute($stmt);

printf("Error #%d: %s.n", mysqli_stmt_errno($stmt), mysqli_stmt_error($stmt));

if(mysqli_stmt_affected_rows($stmt) == 0)

if(!mysqli_stmt_affected_rows($stmt))