SQL to find highest version of multiple updated copies of rows

Question

Hello,
I have an Archive table the stores archived versions of updated rows from the Main table. Each time a Main row is updated, a copy of it is copied to the Archive table with the next version number of a sequence.
The Archive table has three columns: Title -- MessageId -- Version.
Here is some sample data, showing three versions of messageid = 101 and two versions of messageid = 102:
Title -- MessageId -- Version
title abc -- 101 -- 1
title xyz -- 101 -- 2
title mno -- 101 -- 3
title jkl -- 102 -- 1
title opq -- 102 -- 2
My goal is to do a query that might work like this:
select title, messageid, max(version) from Archive group by title, messageid;
-- so that I get this result set:
title mno -- 101 -- 3
title opq -- 102 -- 2
Can somebody please me with the SQL to get this kind of result? Any suggestions are greatly appreciated.
Thank you,
Logan

Answer 1

Here are two generic ways I think will work (haven't tried 'em):
select title, messageid, version
from archive
where (messageid, version) in
  (select messageid, max(version)
   from archive
   group by messageid)
select a.title, a.messageid, a.version
from archive a,
  (select messageid, max(version) as max_version
   from archive
   group by messageid) b
where a.messageid = b.messageid
   and a.version b.max_versionThere's probably a more efficient Oracle-specific way using the anaylytic functions, but I can't think of how to do it at the moment...