+-------+---------+---------+
| title | doc_num | version |
+-------+---------+---------+
| bar   |    1234 |       9 |
| foo   |    1234 |       7 |
| other |    2121 |       7 |
+-------+---------+---------+

##</code><code>##

SELECT title, doc_num, MAX(version) AS version from test GROUP BY title;
# For this example "test" is the table name