$sql = "select id, title from posts where id in (369,378,363)";

$st = $db->prepare($sql);

$st->execute();

$items = "";

while ($row = $st->fetch()){
    $items .= "<div class='linkedsingleup' data-id = " . $row['id'] . ">" . $row['title'] . "</div>nn";
}

echo $items;