Oracle sql how to get start and end dates of weeks between two dates - oracle

Question

I want to get the start and end days of every week between two dates. The dates's format is dd/mm/yyy hh24:mi:ss. I need the weeks in the format dd/mm/yyyy hh24:mi:ss because I have to calculate the days and hours between the start and end day of the week with the times
I wrote this statement
WITH
date_range AS (
SELECT
pdm.des_comercial serie,
pdm.id_material codserie,
ri.id_accion intervencion,
TO_CHAR(NVL(ri.fecha_salida_rev, SYSDATE), 'dd/mm/RRRR') fecha1,
to_char((CASE
WHEN ri.fecha_salida_rev > TO_DATE('18/06/2019', 'dd/mm/yyyy') THEN TO_DATE('18/06/2019', 'dd/mm/yyyy')
WHEN ri.fecha_salida_Rev IS NULL THEN TO_DATE('18/06/2019', 'dd/mm/yyyy')
ELSE ri.fecha_salida_Rev
END),'dd/mm/yyyy hh24:mi:ss') fechasalida,
to_char((CASE
WHEN ri.fecha_entrada_rev < TO_DATE('01/06/2019', 'dd/mm/yyyy') THEN TO_DATE('01/06/2019', 'dd/mm/yyyy')
ELSE ri.fecha_entrada_Rev
END),'dd/mm/yyyy hh24:mi:ss') fechaentrada
,
ri.cod_taller_rev,
ri.COD_MATRICULA,
ri.fecha_entrada_rev start_date,
ri.fecha_salida_rev end_date
FROM
r_intervencion ri,
planificador.pl_dh_material pdm
WHERE
ri.id_accion = ri.amortizada_por
AND ri.causa_entrada = 1
AND ri.tipo_accion = 1
AND pdm.id_material = ri.cod_serie
AND pdm.hasta = 99999999
AND ri.ID_ACCION = 'IM4'
AND ri.fecha_salida_rev BETWEEN TO_DATE('01/06/2019', 'dd/mm/yyyy') AND TO_DATE('18/06/2019', 'dd/mm/yyyy')
),
semanas AS (
SELECT LEVEL "Week"
,to_char(to_date(start_date,'dd/mm/yyyy hh24:mi:ss') + (7 * (LEVEL - 1)),'IW') startweek
,to_char(to_date(start_date ,'dd/mm/yyyy hh24:mi:ss')+ (7 * (LEVEL - 1)),'IW') + 6 endweek
,TO_CHAR(start_date + (7 * (LEVEL - 1)),'IW') "Iso Week",
serie,
codserie,
intervencion,
cod_taller_rev,
cod_matricula,
fechaentrada,
fechasalida,
start_date,
end_date
FROM date_range
CONNECT BY LEVEL <= (to_char(To_date(end_date,'dd/mm/yyyy hh24:mi:ss'),'IW') - to_char(To_date(start_date,'dd/mm/yyyy hh24:mi:ss'),'IW')) / 7 + 1
)
SELECT startweek,
endweek,
to_date(endweek,'dd/mm/yyyy hh24:mi:ss') - to_date(startweek,'dd/mm/yyyy hh24:mi:ss') dias,
serie,
codserie,
intervencion,
cod_taller_rev,
cod_matricula,
start_Date,
end_date,
fechaentrada,
fechasalida,
rd.descripcion
FROM semanas,r_depositos rd
WHERE cod_taller_rev = rd.cod_deposito
When I execute it, I get
Query execution failed
SQL Error [1840] [22008]: ORA-01840: ORA-01840: input value not long enough for date format
The error is in
,to_char(to_date(start_date,'dd/mm/yyyy hh24:mi:ss') + (7 * (LEVEL - 1)),'IW') startweek
,to_char(to_date(start_date ,'dd/mm/yyyy hh24:mi:ss')+ (7 * (LEVEL - 1)),'IW') + 6 endweek
How can I get the startweek and endweek with the format dd/mm/yyyy hh24:mi:ss
EDITED
start_date end_date
20/05/2019 20:00:00 05/06/2019 08:00:00
weeks
20/05/2019 20:00:00 26/05/2019 -> 6 days and xxx hours
27/05/2019 02/06/2019 -> 7 days
03/06/2019 05/06/2019 08:00:00 -> 3 days and xxx hours
I need to calculate the difference in days and hours for each week.
For example between 20/05/2019 20:00:00 and 26/05/2019
and last one between 03/06/2019 and 05/06/2019 08:00:00
My issue is with the calculation
to_date(endweek,'dd/mm/yyyy hh24:mi:ss') - to_date(startweek,'dd/mm/yyyy hh24:mi:ss') dias,
endweek and startweek have to have dd/mm/yyyy hh24:mi:ss

Answer 1

My issue is with the calculation
to_date(endweek,'dd/mm/yyyy hh24:mi:ss') - to_date(startweek,'dd/mm/yyyy hh24:mi:ss') dias,
endweek and startweek have to have dd/mm/yyyy hh24:mi:ss
Oracle dates are stored in an internal format which you generally don't need to worry about. Your application or client formats the date as a string, based on its own setting or your session NLS settings.
When you do something like:
to_date(endweek,'dd/mm/yyyy hh24:mi:ss')
you're really doing:
to_date(to_char(endweek),'dd/mm/yyyy hh24:mi:ss')
and as there is no explicit format mask specified for the implicit to_char() call it used your current session's NLS settings. Depending on the setting it might error; or might corrupt the value - e.g. mixing YY and YYYY masks can lose the century, converting 2019 to 0019. (Given the error you are getting, your NLS settings might be unusual?).
At best you're converting the date value to a string and back to exactly the same date value, which is pointless. You aren't changing the format of the datem because it doesn't have one. The intermediate string does, but you aren't using that, and you can't for calculations (at least without converting back to a date as you are, which again is pointless.)
Oracle has other functions to manipulate date values, including trunc(), so I think you might want something like this - showing the difference in three ways, though there are others and you can format the last one however you want:
with date_range (start_date, end_date) as (
-- dummy data from your example
select to_date('20/05/2019 20:00:00', 'DD/MM/YYYY HH24;MI:SS') as start_date,
to_date('05/06/2019 08:00:00', 'DD/MM/YYYY HH24;MI:SS') as end_date
from dual
),
semanas as (
select level as week,
start_date,
end_date,
greatest(trunc(start_date + (7 * (level - 1)), 'IW'), start_date) as start_week,
least(trunc(start_date + (7 * level), 'IW'), end_date) as end_week
from date_range
connect by level <= (trunc(end_date, 'IW') - trunc(start_date, 'IW')) / 7 + 1
)
select week,
to_char(start_week, 'IW') as iso_week,
to_char(start_week, 'DD/MM/YYYY HH24:MI:SS') as start_week,
to_char(end_week, 'DD/MM/YYYY HH24:MI:SS') as end_week,
end_week - start_week as diff_num,
numtodsinterval(end_week - start_week, 'DAY') as diff_interval,
to_char(date '1999-12-31' + (end_week - start_week), 'FMDD "days" HH24 "hours"') as diff_words
from semanas;
WEEK IS START_WEEK END_WEEK DIFF_NUM DIFF_INTERVAL DIFF_WORDS
---------- -- ------------------- ------------------- ---------- ------------------- ----------------
1 21 20/05/2019 20:00:00 27/05/2019 00:00:00 6.16666667 +06 04:00:00.000000 6 days 4 hours
2 22 27/05/2019 00:00:00 03/06/2019 00:00:00 7 +07 00:00:00.000000 7 days 0 hours
3 23 03/06/2019 00:00:00 05/06/2019 08:00:00 2.33333333 +02 08:00:00.000000 2 days 8 hours
As currently written the connect by only works properly if the date_range CTE generates a single value; if you actually get multiple rows back from your real query then you'll have to do a bit more work, or switch to recursive CTEs, or cross join/apply, depending on your Oracle version.

Answer 2

Your endweek calculation is
to_char(to_date(start_date ,'dd/mm/yyyy hh24:mi:ss')+ (7 * (LEVEL - 1)),'IW') + 6 endweek
This attempts to add the number 6 to a character string. I suspect that what you wanted was
to_char(to_date(start_date ,'dd/mm/yyyy hh24:mi:ss') + (7 * (LEVEL - 1) + 6),'IW') endweek
Here I've moved the + 6 so you're adding 6 to the date value, rather than to a character string.