Connect by and level - hour interval - sql

Question

I have the following data:
ID SESSION START_DATE END_DATE
1 A 01/01/2016 22:35 02/01/2016 02:35
1 B 02/01/2016 02:35 02/01/2016 04:45
2 A 01/01/2016 00:00 01/01/2016 02:00
2 B 01/01/2016 02:00 01/01/2016 03:30
And I need to return like this:
ID SESSION START_DATE END_DATE
1 A 01/01/2016 22:35 01/01/2016 22:59
1 A 01/01/2016 23:00 01/01/2016 23:59
1 A 02/01/2016 00:00 02/01/2016 00:59
1 A 02/01/2016 01:00 02/01/2016 01:59
1 A 02/01/2016 02:00 02/01/2016 02:35
1 B 02/01/2016 02:35 02/01/2016 02:59
1 B 02/01/2016 03:00 02/01/2016 03:59
1 B 02/01/2016 04:00 02/01/2016 04:45
2 A 01/01/2016 00:00 01/01/2016 00:59
2 A ...
any help?

Answer 1

You can try something like this:
SELECT DISTINCT session,
id,
st,
end
FROM ( SELECT DECODE(LEVEL, 1, start_date, TRUNC(start_date, 'HH') + (LEVEL - 1) / 24) st,
PRIOR id p_id,
id,
PRIOR session p_session,
session,
LEAST(end_date, TRUNC(start_date, 'HH') + (LEVEL) / 24 - 1 / 24 / 60) end
FROM tab
CONNECT BY LEVEL <= EXTRACT(HOUR FROM end_date - start_date) + 1)
WHERE ( p_id = id
AND p_session = session)
OR (p_id IS NULL)
I would like to avoid the usage of DISTINCT, but could not find a way, hope someone else could give a better solution

Answer 2

Here is a solution, you just have to play a little with hour extractions:
create table connect_by_hour_test(id number, sess varchar2(1), start_date date, end_date date);
insert into connect_by_hour_test (id, sess, start_date, end_date) values (1, 'A', to_date('01/01/2016 22:30', 'dd/mm/yyyy hh24:mi'), to_date('02/01/2016 02:35', 'dd/mm/yyyy hh24:mi'));
insert into connect_by_hour_test (id, sess, start_date, end_date) values (1, 'B', to_date('02/01/2016 02:35', 'dd/mm/yyyy hh24:mi'), to_date('02/01/2016 04:45', 'dd/mm/yyyy hh24:mi'));
insert into connect_by_hour_test (id, sess, start_date, end_date) values (2, 'A', to_date('01/01/2016 00:00', 'dd/mm/yyyy hh24:mi'), to_date('01/01/2016 02:00', 'dd/mm/yyyy hh24:mi'));
insert into connect_by_hour_test (id, sess, start_date, end_date) values (2, 'B', to_date('01/01/2016 02:00', 'dd/mm/yyyy hh24:mi'), to_date('01/01/2016 03:30', 'dd/mm/yyyy hh24:mi'));
commit;
with max_level as (
select id, sess, ceil((end_date - start_date) / (1/24)) as val from connect_by_hour_test ) -- get the max number of iterations for each (id, sess) pair
select distinct
id,
sess,
decode(level, 1, to_char(start_date, 'dd/mm/yyyy hh24:mi'), to_char(trunc(start_date, 'hh24') + 1/24 * level - 1/24, 'dd/mm/yyyy hh24:mi')) start_date, -- if first iteration in pair show the start_date, otherwise show the start date, plus the number of hours for the current iteration(first iteration - 1 hour, 2nd iteration - two hours, etc) minus one minute
decode(level, (select val from max_level ml where ml.id = src.id and ml.sess = src.sess), to_char(end_date, 'dd/mm/yyyy hh24:mi'), to_char(trunc(start_date, 'hh24') + 1/24 * level - 1/24/60, 'dd/mm/yyyy hh24:mi')) end_date -- if last iteration show end_date, otherwise show value from previous iteration plus one minute
from
connect_by_hour_test src
connect by
trunc(start_date, 'hh24') + 1/24 * (level - 1) <= end_date order by 1,2;
Edit: Corrections made after feedback, added step to be level - 1 and max_level calculated as ceil, instead of trunc, of end_date - start_date

Answer 3

select level,
NR_ATENDIMENTO,
CD_SETOR_ATENDIMENTO,
greatest(DT_ENTRADA_UNIDADE, trunc(DT_ENTRADA_UNIDADE+(level-1)/24, 'hh24')) DT_ENTRADA_UNIDADE,
to_char(trunc(DT_ENTRADA_UNIDADE, 'hh24') + 1/24 * level - 1/24/60, 'dd/mm/yyyy hh24:mi:ss') DT_SAIDA_UNIDADE
from
(
SELECT
CD_SETOR_ATENDIMENTO,
NR_SEQ_INTERNO,
DT_ENTRADA_UNIDADE,
nvl(DT_SAIDA_UNIDADE,sysdate) DT_SAIDA_UNIDADE,
NR_ATENDIMENTO
FROM ATEND_PACIENTE_UNIDADE
WHERE OBTER_TIPO_UNIDADE_ATEND(NR_ATENDIMENTO, NR_SEQ_INTERNO, IE_PASSAGEM_SETOR) NOT IN ('S')
AND nr_atendimento = 831838
ORDER BY NR_ATENDIMENTO,
CD_SETOR_ATENDIMENTO,
DT_ENTRADA_UNIDADE DESC
)
WHERE 1=1
CONNECT BY ROWID=PRIOR ROWID
and trunc(DT_ENTRADA_UNIDADE, 'hh24') + 1/24 * (level - 1) <= nvl(DT_SAIDA_UNIDADE,sysdate)
AND PRIOR SYS_GUID() IS NOT NULL
order by 2,3,4;