Select number of rows changed within an hour

Question

Hi all, i below are samples of my data
name: age : changed_date_time
peter: 13: 2/10/06 13:45:30
james: 14: 2/10/06 13:30:45
justin:17: 2/10/06 14:05:00
john:20: 4/10/06 05:10:31
my desired result is
changed_date_time : number of records
2/10 13hrs : 2
2/10 14hrs : 1
4/10 05hrs : 1
what i wrote wasselect to_char ( changed_date_time , 'dd/mm hh24'),count (*)
from table1
group by changed_date_timeI tried to include a sum function within my query, i was not able to achieve my desired results. Can someone advise?

Answer 1

Change your group by clause
with t as
select 'peter' name,13 age, to_date('2/10/06 13:45:30','dd/mm/yy hh24:MI:SS') changed_date_time from dual
union all
select 'james',14,to_date('2/10/06 13:30:45','dd/mm/yy hh24:MI:SS') from dual
union all
select 'justin',17, to_date('2/10/06 14:05:00','dd/mm/yy hh24:MI:SS') from dual
union all
select 'john',20,to_date('4/10/06 05:10:31','dd/mm/yy hh24:MI:SS') from dual
select to_char(changed_date_time,'DD/MM hh24')||'hrs' ||' : '||count(1) from t
group by to_char(changed_date_time,'DD/MM hh24')