Select all days in a week, when calendarweek is given - sql

Question

certainly something very simple, but for an application I would like to know how, if I know the calendar week, I can display the first to the last day of the week per row.
Currently, I am only shown the day in which content is present.
I would like to have 7 days displayed (as date, not necessarily with name) whether they are empty or not.
SELECT
MIN( TO_CHAR(LP_BELEGUNG.GEN_DATUM,'DD.MM.YYYY')) AS GRD_ROW_ID
, COUNT( DISTINCT
CASE
WHEN LP_BELEGUNG.ART = 1 THEN LP_BELEGUNG.LP_BELEGUNG_ID
ELSE NULL
END ) AS ANZAHL_ART_1
, COUNT( DISTINCT
CASE
WHEN LP_BELEGUNG.ART = 2 THEN LP_BELEGUNG.LP_BELEGUNG_ID
ELSE NULL
END ) AS ANZAHL_ART_2
, COUNT( DISTINCT
CASE
WHEN LP_BELEGUNG.ART = 3 THEN LP_BELEGUNG.LP_BELEGUNG_ID
ELSE NULL
END ) AS ANZAHL_ART_3
, COUNT( DISTINCT
CASE
WHEN LP_BELEGUNG.ART = 99 THEN LP_BELEGUNG.LP_BELEGUNG_ID
ELSE NULL
END ) AS ANZAHL_ART_4
FROM
LP_BELEGUNG
WHERE
TO_CHAR(LP_BELEGUNG.GEN_DATUM, 'WW') = 37 --the calendar week

Answer 1

If you want one row per day, for a week number in a given year, then you can generate all the dates in that week and use an outer join to look for matching rows in your table, if there are any.
Unfortunately Oracle doesn't supply a simple way to get a date from a week number, but based on how the WW element is defined you can start from the first day of the year and add the appropriate number of days to get the start of the week:
select trunc(sysdate, 'YYYY') + (7 * 37) - 7 from dual;
TRUNC(SYSDATE,'YYYY')+(7*37)-7
10-SEP-22
... where 37 is the week number, and I've assumed you're looking at the current year (if not, use a fixed date like date '2022-01-01' instead of trunc(sysdate)).
You can then get all the days in that week with a hierarchical query:
select trunc(sysdate, 'YYYY') + (7 * 37) + level - 8
from dual
connect by level <= 7;
TRUNC(SYSDATE,'YYYY')+(7*37)+LEVEL-8
10-SEP-22
11-SEP-22
12-SEP-22
13-SEP-22
14-SEP-22
15-SEP-22
16-SEP-22
Then use those values in an inline view or CTE, and left-join to your table using a date range (to allow for non-midnight times but still allowing an index on that column to be used), grouping by the date:
with cte (dt) as (
select trunc(sysdate, 'YYYY') + (7 * 37) + level - 8
from dual
connect by level <= 7
)
SELECT
TO_CHAR(cte.dt, 'DD.MM.YYYY') AS GRD_ROW_ID
, COUNT( DISTINCT
CASE
WHEN LP_BELEGUNG.ART = 1 THEN LP_BELEGUNG.LP_BELEGUNG_ID
ELSE NULL
END ) AS ANZAHL_ART_1
, COUNT( DISTINCT
CASE
WHEN LP_BELEGUNG.ART = 2 THEN LP_BELEGUNG.LP_BELEGUNG_ID
ELSE NULL
END ) AS ANZAHL_ART_2
, COUNT( DISTINCT
CASE
WHEN LP_BELEGUNG.ART = 3 THEN LP_BELEGUNG.LP_BELEGUNG_ID
ELSE NULL
END ) AS ANZAHL_ART_3
, COUNT( DISTINCT
CASE
WHEN LP_BELEGUNG.ART = 99 THEN LP_BELEGUNG.LP_BELEGUNG_ID
ELSE NULL
END ) AS ANZAHL_ART_4
FROM
cte
LEFT JOIN
LP_BELEGUNG
ON
LP_BELEGUNG.GEN_DATUM >= cte.dt AND LP_BELEGUNG.GEN_DATUM < cte.dt + 1
GROUP BY
cte.dt
ORDER BY
cte.dt
With some sample data to mimic your original result, that gives:
GRD_ROW_ID
ANZAHL_ART_1
ANZAHL_ART_2
ANZAHL_ART_3
ANZAHL_ART_4
10.09.2022
0
0
0
0
11.09.2022
0
0
0
0
12.09.2022
0
0
0
0
13.09.2022
0
0
0
0
14.09.2022
0
0
0
0
15.09.2022
0
0
0
0
16.09.2022
1
0
0
7
fiddle

Answer 2

Here is a set of dates counted and divided to days of the week using to_char and pivot.
select *
from
(
select dt
,to_char(dt, 'D') as dow
from t
) t
pivot (count(dt) for dow in('1', '2', '3', '4', '5', '6', '7')) p
'1'
'2'
'3'
'4'
'5'
'6'
'7'
1
1
0
0
1
3
1
Fiddle

Answer 3

Use conditional aggregation:
SELECT TO_CHAR(MIN(GEN_DATUM),'DD.MM.YYYY') AS GRD_ROW_ID,
COUNT( DISTINCT
CASE
WHEN ART = 1
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 0
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_1_DAY1,
COUNT( DISTINCT
CASE
WHEN ART = 1
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 1
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_1_DAY2,
-- ...
COUNT( DISTINCT
CASE
WHEN ART = 1
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 6
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_1_DAY7,
COUNT( DISTINCT
CASE
WHEN ART = 2
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 0
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_2_DAY1,
COUNT( DISTINCT
CASE
WHEN ART = 2
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 1
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_2_DAY2,
-- ...
COUNT( DISTINCT
CASE
WHEN ART = 2
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 6
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_2_DAY7,
COUNT( DISTINCT
CASE
WHEN ART = 3
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 0
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_3_DAY1,
COUNT( DISTINCT
CASE
WHEN ART = 3
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 1
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_3_DAY2,
-- ...
COUNT( DISTINCT
CASE
WHEN ART = 3
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 6
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_3_DAY7,
COUNT( DISTINCT
CASE
WHEN ART = 99
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 0
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_4_DAY1,
COUNT( DISTINCT
CASE
WHEN ART = 99
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 1
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_4_DAY2,
-- ...
COUNT( DISTINCT
CASE
WHEN ART = 99
AND TRUNC(gen_datum) - TRUNC(gen_datum, 'WW') = 6
THEN LP_BELEGUNG_ID
END
) AS ANZAHL_ART_4_DAY7
FROM LP_BELEGUNG
WHERE TO_CHAR(GEN_DATUM, 'WW') = 37