how to display each article total comments

I have two tables which I have joined. The query looks like this:

SELECT *, AVG(rate)
FROM comments c 
LEFT JOIN supps s     
on c.tutorialid = s.tutid 
WHERE category = 'Protein' 
GROUP BY tutorialid
ORDER BY $orderby $sort LIMIT $startrow,$limit";

And I have the code below to get the total comments:

//find the number of comments
    $commentNum = mysql_num_rows($result);

When I use echo $commentNum, it displays the total for all comments on every row for example if I had:

echo "".$row['title'] ."<br>";
echo $commentNum .

It would give me the total comments for all th开发者_运维百科e posts rather the total for each individual post. Can anyone tell me what I have got wrong? How can I get total comment for each post?

I would try adding COUNT(*) in your initial SELECT. So your query would read

SELECT *, COUNT(*), AVG(rate)
FROM comments c 
LEFT JOIN supps s     
ON c.tutorialid = s.tutid 
WHERE category = 'Protein' 
GROUP BY tutorialid
ORDER BY $orderby $sort LIMIT $startrow,$limit";