How to select only the latest rows for each user?

Question

My table looks like this:

id  | user_id | period_id | completed_on
----------------------------------------
1   | 1       | 1         | 2010-01-01
2   | 2                


        

Answer 1

try this:

SELECT t.Id, t.User_Id, t.Period_Id, t.Completed_On
FROM table1 t
JOIN (SELECT Max(completed_on) Max_Completed_On, t.User_Id
FROM table1 t
GROUP BY t.User_ID) t2 ON t.User_Id = t2.User_Id AND t.Completed_On = t2.Max_Completed_On

DEMO HERE