how to get last businessday of last month in oralce - oracle

Question

I have data like this my table
2020-01-01 H
2020-01-02 B
2020-01-03 B
2020-01-04 B
.
2020-01-29 B
2020-01-30 H
2020-01-31 H
2020-01-02 H
2020-02-02 H
2020-02-03 B
2020-02-04 B
2020-02-05 B
.
now my problem is in the current month i need to check third business day i.e in this case 2020-02-05 i need to get last business day of last month. i.e.2020-01-29

Answer 1

By adding 2 columns:
row_number() over(partition by trunc(date_value,'MM'), day_type order by date_value) as rn_month_asc,
row_number() over(partition by trunc(date_value,'MM'), day_type order by date_value desc) as rn_month_desc
in a month the 3rd business day will have rn_month_asc=3 and day_type ='B' and the latest business day will have rn_month_desc=1 and day_type ='B', and easy to query other situations if you need to.

Answer 2

in the current month I need to check third business day
From Oracle 12, you can use:
SELECT date_value
FROM table_name
WHERE TRUNC(SYSDATE, 'MM') <= date_value
AND date_value < ADD_MONTHS(TRUNC(SYSDATE, 'MM'), 1)
AND day_type = 'B'
ORDER BY date_value ASC
OFFSET 2 ROWS
FETCH NEXT ROW ONLY;
Which, for the sample data:
CREATE TABLE table_name (date_value, day_type) AS
SELECT DATE '2020-01-01', 'H' FROM DUAL UNION ALL
SELECT DATE '2020-01-02', 'B' FROM DUAL UNION ALL
SELECT DATE '2020-01-03', 'B' FROM DUAL UNION ALL
SELECT DATE '2020-01-04', 'B' FROM DUAL UNION ALL
SELECT DATE '2020-01-05', 'B' FROM DUAL UNION ALL
SELECT DATE '2020-01-28', 'B' FROM DUAL UNION ALL
SELECT DATE '2020-01-29', 'B' FROM DUAL UNION ALL
SELECT DATE '2020-01-30', 'H' FROM DUAL UNION ALL
SELECT DATE '2020-01-31', 'H' FROM DUAL UNION ALL
SELECT DATE '2020-01-02', 'H' FROM DUAL UNION ALL
SELECT DATE '2020-02-02', 'H' FROM DUAL UNION ALL
SELECT DATE '2020-02-03', 'B' FROM DUAL UNION ALL
SELECT DATE '2020-02-04', 'B' FROM DUAL UNION ALL
SELECT DATE '2020-02-05', 'B' FROM DUAL;
If the current month was 2020-01 then the output is:
DATE_VALUE
04-JAN-20
I need to get last business day of last month
SELECT date_value
FROM table_name
WHERE ADD_MONTHS(TRUNC(SYSDATE, 'MM'), -1) <= date_value
AND date_value < TRUNC(SYSDATE, 'MM')
AND day_type = 'B'
ORDER BY date_value DESC
FETCH FIRST ROW ONLY;
If the current month is 2020-02 then the output is:
DATE_VALUE
29-JAN-20
fiddle