Ahh. Then again, with a real database with subselects, that'd be:

SELECT title, doc_num, version
FROM atable
WHERE  (doc_num,  version) IN (
  SELECT doc_num, MAX(version) FROM atable GROUP BY doc_num
);
[download]

Again, this won't work in puny MySQL. PostgreSQL or better, baby!

-- Randal L. Schwartz, Perl hacker