Query to display time gap information

Question

Question
How do you produce an hourly view of time, based on 2 dates?
Script to create demo table and data
create table komponenter ( komp_id number, issue_begin date, issue_end date);
declare
big_bang_tim date := to_date('05-05-2011 13:12:11', 'DD-MM-YYYY HH24:MI:SS');
begin
insert into komponenter values (1, big_bang_tim - 4.52, big_bang_tim - 4.51);
insert into komponenter values (1, big_bang_tim - 4.46, big_bang_tim - 4.41);
insert into komponenter values (1, big_bang_tim - 4.38, big_bang_tim - 4.21);
commit;
end;
Query:
What I'm trying to do is get information about how much time of every hour, an issue has been "active". So from the data above, the following output is what I'm trying to get:
<pre>
komp_id day_hour issue_activity
====== =========== ==================
1 01-05-2011 00 14 minutes and 24 seconds
1 01-05-2011 01 0 minutes
1 01-05-2011 02 50 minutes and 13 seconds
1 01-05-2011 03 21 minutes and 47 seconds
1 01-05-2011 04 55 minutes and 01 seconds
1 01-05-2011 05 60 minutes
1 01-05-2011 06 60 minutes
1 01-05-2011 07 60 minutes
1 01-05-2011 08 9 minutes and 47 seconds
1 01-05-2011 09 0 minutes
1 01-05-2011 10 0 minutes
</pre>

Answer 1

Hi,
Welcome to the forum!
Here's one way:
WITH     all_hours     AS
     SELECT     TO_DATE ( '01-05-2011 00'
                     , 'DD-MM-YYYY HH24'
               ) + ( (LEVEL - 1)
                   / 24
                   )          AS hour_begin
     FROM     dual
     CONNECT BY     LEVEL     <= 11
,     got_seconds     AS
     SELECT       k.komp_id
     ,       h.hour_begin
     ,       ROUND ( SUM ( GREATEST ( ( LEAST    (k.issue_end,   h.hour_begin + (1 / 24))
                            - GREATEST (k.issue_begin, h.hour_begin)
                          , 0
                      )* 24 * 60 * 60
                  )          AS seconds
     FROM          komponenter     k
     CROSS JOIN     all_hours     h
     GROUP BY  k.komp_id
     ,       h.hour_begin
SELECT       komp_id
,       TO_CHAR ( hour_begin
            , 'DD-MM-YYYY HH24'
            )               AS day_hour
,       TRUNC (seconds / 60) || ' minutes'
                      || CASE
                         WHEN  MOD (seconds, 60) > 0
                         THEN  ' and ' || MOD (seconds, 60)
                                    || ' seconds'
                           END     AS issue_activity
FROM       got_seconds
ORDER BY  komp_id
,       hour_begin
;Output:
`  KOMP_ID    DAY_HOUR           ISSUE_ACTIVITY
         1    01-05-2011 00      14 minutes and 24 seconds
         1    01-05-2011 01      0 minutes
         1    01-05-2011 02      50 minutes and 13 seconds
         1    01-05-2011 03      21 minutes and 47 seconds
         1    01-05-2011 04      55 minutes and 1 seconds
         1    01-05-2011 05      60 minutes
         1    01-05-2011 06      60 minutes
         1    01-05-2011 07      60 minutes
         1    01-05-2011 08      9 minutes and 47 seconds
         1    01-05-2011 09      0 minutes
         1    01-05-2011 10      0 minutesThe approach is similar to Nicosa's, but this shows the hours with 0 minutes, as you requested.