This works:

"SELECT * FROM mlf2_entries, mlf2_userdata
WHERE mlf2_userdata.user_id  = mlf2_entries.user_id
GROUP BY tid ORDER BY last_reply
DESC LIMIT 0, 5";

This shows the latest postings, original author and date of the latest reply. However, I want the username of the last person who replied. How can I do that?

If I use this query:

"SELECT * FROM mlf2_entries, mlf2_userdata
WHERE mlf2_userdata.user_id  = mlf2_entries.user_id
GROUP BY pid ORDER BY last_reply
DESC LIMIT 0, 5";

I get this output:

• Lorem ipsum thread
  by Ghost on 2015-12-07 09:05:58
  
• Lorem ipsum thread
  by Evil Knievel on 2015-12-07 09:05:58
  
• Another thread
  by Doc on 2015-12-07 09:05:58
  
• Lorem ipsum thread
  by Caroline on 2015-12-07 09:05:58
  
• Another thread
  by Marko on 2015-12-06 20:23:55

This is partly what I want, but I only want to show each topic once with the latest posting date and the last person who replied.