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ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
CREATE TABLE my_table ( c_day ) AS
SELECT LEVEL FROM DUAL CONNECT BY LEVEL <= 31;
31 rows affected
SELECT C_DAY,
LEAST(
TRUNC(TRUNC(SYSDATE) + 210, 'MM') + C_DAY - 1,
LAST_DAY(TRUNC(SYSDATE) + 210)
) AS result
FROM MY_TABLE
ORDER BY c_day
| C_DAY | RESULT |
|---|---|
| 1 | 2023-09-01 00:00:00 |
| 2 | 2023-09-02 00:00:00 |
| 3 | 2023-09-03 00:00:00 |
| 4 | 2023-09-04 00:00:00 |
| 5 | 2023-09-05 00:00:00 |
| 6 | 2023-09-06 00:00:00 |
| 7 | 2023-09-07 00:00:00 |
| 8 | 2023-09-08 00:00:00 |
| 9 | 2023-09-09 00:00:00 |
| 10 | 2023-09-10 00:00:00 |
| 11 | 2023-09-11 00:00:00 |
| 12 | 2023-09-12 00:00:00 |
| 13 | 2023-09-13 00:00:00 |
| 14 | 2023-09-14 00:00:00 |
| 15 | 2023-09-15 00:00:00 |
| 16 | 2023-09-16 00:00:00 |
| 17 | 2023-09-17 00:00:00 |
| 18 | 2023-09-18 00:00:00 |
| 19 | 2023-09-19 00:00:00 |
| 20 | 2023-09-20 00:00:00 |
| 21 | 2023-09-21 00:00:00 |
| 22 | 2023-09-22 00:00:00 |
| 23 | 2023-09-23 00:00:00 |
| 24 | 2023-09-24 00:00:00 |
| 25 | 2023-09-25 00:00:00 |
| 26 | 2023-09-26 00:00:00 |
| 27 | 2023-09-27 00:00:00 |
| 28 | 2023-09-28 00:00:00 |
| 29 | 2023-09-29 00:00:00 |
| 30 | 2023-09-30 00:00:00 |
| 31 | 2023-09-30 00:00:00 |