Question

I have two tables ‘Comments’ and ‘Likes’ and I can show all the comments that have been liked and order them by when the comments where added. What I can’t seem to do at the moment is order the comments according to when they were liked.

This is what I have at the moment:

SELECT * 
FROM comments AS c 
WHERE EXISTS (
    SELECT * 
    FROM likes AS l 
    WHERE c.commentID=l.commentID)

Could anyone help me with the SQL to show the comments in order with the one that was most recently liked first and so on…

Just to add – I only want to show the comment once and avoid showing any comments that have not been liked.

Answer 1

If you have multiple likes for a given comment, then you need an aggregation, such as:

SELECT c.*
FROM comments c join
     (select l.commentId, MIN(likedate) as FirstLikeDate, MAX(likedate) as MaxLikeDate
      from likes l
      group by l.commentId
     ) l
     on c.commentId = l.CommentId
order by MaxLikeDate desc