MySQL SELECT from multiple tables, multiple GROUP BY and group_concat?

Question

I have three tables which I want to query in MySQ. As follows:

**Table: Leaderboard**
Name  | Score
------------
James | 1
Steve | 2
Dave  | 5

**Table: Acti         


        

Answer 1

SELECT Leaderboard.Name,
  (SELECT Actions.Action
   FROM Actions
   WHERE Actions.Name = Leaderboard.Name
     AND Actions.Action LIKE 'Ate%'
   ORDER BY Time DESC
   LIMIT 1
  ) AS Latest_Action,
  GROUP_CONCAT(Items.Item
               ORDER BY Items.Time DESC
               SEPARATOR ', '
              ) AS Items
FROM Leaderboard
     LEFT JOIN Items ON Leaderboard.Name = Items.Name
GROUP BY Leaderboard.Name
HAVING Latest_Action IS NOT NULL
ORDER BY Leaderboard.Score DESC

Result verified in SQL Fiddle.