data by every hour

Hi guys, how do i get this

i want the count of cjobid for every hour,that is group by date(every hour) and by ctype for the last 3 days.below is the table structure.

can some one please help me.Thanks

customerjobs
-------------
cjobid number(10)
ctype varchar2(55)
cdate date

Group By to_char(cdate, 'YYYYMMDDHH24'), ctype

Or

Group By trunc(cdate, 'HH24'), ctype

thanks for the help .I will try this

ramana