ora-00979

'group by' works on MySQL, but not Oracle

Hi - I have a query that works on MySQL but doesn't work on Oracle, and I'm trying to convert. This is my table: unique_row_id http_session_id page_name page_hit_timestamp ---------------------------------------------------------------- 0 123456789 index.html 2010-01-20 15:00:00 1 123456789 i...