im running a query that usses 3 tabels "post, likes and comment" i need to get the ammount of likes and comments the post has got, and at the same time get the basic info from the post table so im using the query bellow but the problem is that it copys the value likeAmount to commentAmount if likes is bigger unless comments is 0.
SELECT post.*, COUNT(likes.id) as 'LikeAmount', COUNT(comment.id) as 'commentAmount' FROM post
LEFT JOIN likes ON post.id = likes.post
LEFT JOIN comment ON post.id = comment.post
GROUP BY post.id
ORDER BY LikeAmount DESC"
so that doesnt work but when i add distinct it does work, so when its like this:.
SELECT post.*, COUNT(distinct likes.id) as 'LikeAmount', COUNT(distinct comment.id) as 'commentAmount' FROM post
LEFT JOIN likes ON post.id = likes.post
LEFT JOIN comment ON post.id = comment.post
GROUP BY post.id
ORDER BY LikeAmount DESC";
i dont see why it works with distinct and doesnt with out, and does distinct mather performance wise or does it make no diffrence sinds it will be used in a website that has a lott of trafic..