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WITH da(date_h) AS (
SELECT '2019-12-30' date_h FROM dual union all
SELECT '2018-12-30' date_h FROM dual union all
SELECT '2020-02-20' date_h FROM dual union all
SELECT '2019-08-30' date_h FROM dual
)
SELECT date_h FROM da WHERE
to_date(date_h, 'yyyy-mm-dd') >= to_date('2019-04-01','yyyy-mm-dd')
AND
to_date(date_h, 'yyyy-mm-dd') <= LAST_DAY(ADD_MONTHS(sysdate, -1)) --to_date('2020-01-31','yyyy-mm-dd')
| DATE_H |
|---|
| 2019-12-30 |
| 2019-08-30 |