Question

I’m making an application that is similar to stackoverflow in that it has ratings for questions and answers and I also have tabs that show comments by oldest, newest and votes. I’m having trouble sorting by votes.

Here is my function:

 /**
     *
     * @param int $threadid
     * @param string $tab
     * @param object $voting referencing Voting.class.php (may not be needed)
     * @return database query/array 
     */
    public function getComments($threadid, $tab = 'oldest', $voting = null) {
        if ($tab == 'oldest') {
            $sql = "SELECT * FROM comments WHERE threadid = :threadid ORDER BY date ASC";
        } else if ($tab == 'newest') {
            $sql = "SELECT * FROM comments WHERE threadid = :threadid ORDER BY date DESC";
        } else if ($tab == 'votes') {
            //i dont know what to do here? read below for more explanation
        } else {
            $sql = "SELECT * FROM comments WHERE threadid = :threadid ORDER BY date ASC";
        }

        $stmt = $this->db->prepare($sql);
        $stmt->bindParam(':threadid', $threadid);
        $stmt->execute();
        $row = $stmt->fetchAll(PDO::FETCH_ASSOC);
        return $row;
    }

Here is my database design:

**comments:** | id | userid | threadid | message | date |

**commentsrating:** | userid | commentid | voteup | votedown |

If ratings are in a separate table from comments is it possible to make a query for $tab == 'votes' that will conform with the rest of the code?

and finally HTML:

<?php //Get comments
if (isset($_GET['tab'])) {
    $getComments = $thread->getComments($threadid, $_GET['tab'], $voting);
} else {
    $getComments = $thread->getComments($threadid);
} ?>

    <?php for ($i = 0; $i < count($getComments); $i++) { ?>
               <p>
    <?php echo $getComments[$i]['message']; ?>
               </p>
               <p>  
                   <span class="bid_votes_count" id="bid_votes_count<?php echo $getComments[$i]['id'] ?>">
    <?php echo $voting->getEffectiveCommentVotes($getComments[$i]['id']) . " votes"; ?>
                   </span>

                   <span class="bid_vote_buttons" id="bid_vote_buttons<?php echo $getComments[$i]['id'] ?>">
                      <a href="javascript:;" class="bid_vote_up" id="<?php echo $getComments[$i]['id'] ?>"></a>
                      <a href="javascript:;" class="bid_vote_down" id="<?php echo $getComments[$i]['id'] ?>"></a>
                  </span>
              </p>
    <?php } ?>

Thanks in advance!

Answer 1

Add rating field to the comments table and maintain it manually or with trigger on commentsrating table.

Obviously, put there pre-calculated value of the rating and now you are able to have a simple and terrible fast question to perform.