Following query will return the records grouped by every hour
SELECT TRUNC (action_time, 'HH24') hours,
COUNT (TO_CHAR (action_time, 'HH24')) RECORDS
FROM pfl_performance_logs
WHERE action_time BETWEEN TO_DATE ('02/11/2007 00:00:00', 'DD/MM/YYYY HH24:MI:SS')
AND TO_DATE ('11/01/2008 00:00:00', 'DD/MM/YYYY HH24:MI:SS')
GROUP BY TRUNC (action_time, 'HH24')
Also, we can use the above query to group records on day (DDD, DD), month (month, mon, mm), year (YYYY, YY), quarter (Q), week (WW, IW) etc.
Enjoy QUERYING
