Group By Number of hours in a day

Question

Hi
I need to write a SQL query to group by my records in hours of day.
For example -
00:00:00 - 00:59:59 - Some Data (There can be more than 1 row for each time slot)
00:00:00 - 00:59:59 - Some Data (There can be more than 1 row for each time slot)
00:00:00 - 00:59:59 - Some Data (There can be more than 1 row for each time slot)
01:00:00 - 01:59:59 - Some Data (There can be more than 1 row for each time slot)
01:00:00 - 01:59:59 - Some Data (There can be more than 1 row for each time slot)
02:00:00 - 02:59:59 - Some Data (There can be more than 1 row for each time slot)
23:00:00 - 23:59:59 - Some Data (There can be more than 1 row for each time slot)
23:00:00 - 23:59:59 - Some Data (There can be more than 1 row for each time slot)
23:00:00 - 23:59:59 - Some Data (There can be more than 1 row for each time slot)
Please advice

Answer 1

EXAMPLE
SQL> l
  1  select to_chaR(hh,'HH24' ), count(*)
  2  from
  3  ( select sysdate+level/23 hh from dual connect by level <125)
  4* group by to_chaR(hh,'HH24' )
SQL> /
TO   COUNT(*)
04          6
08          5
09          5
00          6
07          5
13          5
17          5
01          6
11          5
12          5
18          5
21          5
22          6
16          5
19          5
20          5
02          6
03          6
05          6
10          5
15          5
06          6
23          6
23 rows selected.