You can use the sql limit clause.
SELECT * FROM comment LIMIT 0,5
- , , - .
, :
SELECT * FROM comment LIMIT ((page_number-1)*5),5;
(1 2 3....), .
<a href="comment.php?page=5">5</a>
, sql.
$start = ($_GET['page'] - 1)*5;
$sql = "SELECT * FROM comment LIMIT $start,5";