Oracle, split a time duration row by one hour period

Question

I\'m working on oracle db and I\'m not quite good at Oracle. I\'m trying to split a row by one hour period.

For example, if a time row has given as below,

St

Answer 1

Slightly modified version of the query by . The earlier query did not work in some cases say from date/time is 2:37 am and to date is 6:10 am.

WITH date1 AS (
  SELECT to_date('2017-07-26 02:37:00 AM','yyyy-MM-dd hh12:mi:ss am') dt2,
         to_date('2017-07-26 06:10:00 PM','yyyy-MM-dd hh12:mi:ss am') dt1 FROM DUAL
)
select TO_CHAR (greatest(dt2, trunc(dt2+(level-1)/24, 'hh24')),
    'dd-MON-yyyy HH12:MI:SS AM') FROM_DT,
    TO_CHAR (  least(dt1, trunc(dt2+(level)/24, 'hh24'),
    'dd-MON-yyyy HH12:MI:SS AM') TO_DT
    from date1 connect by level <= floor(
        (trunc(dt1,'HH')-trunc(dt2,'HH'))  *24) + case when (
             dt1 <> trunc(dt1,'HH')
        ) then 1 else 0 end

Answer 2

I have bulit a basic query, you can work around it and get what you want.

select greatest(Start_time, trunc(Start_time+(level-1)/24, 'hh24')), 
least(End_time, trunc(Start_time+(level)/24, 'hh24'))
from log_table 
connect by level <= floor((dt1-dt2)*24)+1;

Example at sqlfiddle:

http://sqlfiddle.com/#!4/82625/29