Question

This should be fairly simple, however I am stuck with it.

when i do the query

SELECT * FROM `inbox` where toid=4 or fromid=4 order by time desc

, i get:

id  toid    fromid  message           time
23  48101   4   hello call me     12/23/2011 12:27
6   34584   4   hi there      12/22/2011 15:42
5   34584   4   how are you   12/22/2011 14:08
4   34584   4   say hello     12/22/2011 14:07
3   34584   4   whats up      12/22/2011 14:07
2   4   34584   nice picture      11/24/2010 0:00
1   4   2   this is very interesting!   12/23/2008 0:00

Now, I need to group the conversations between user 4 and other users each to one row with last message (like facebook messages do).

does anyone know the best way to do that?

Thank you!

Answer 1

SQL Fiddle

select i.id, toid, fromid, message, `time`
from
    inbox i
    inner join (
        select max(id) as id
        from inbox
        where toid = 4 or fromid = 4
        group by greatest(toid, fromid), least(toid, fromid)
    ) s on i.id = s.id