您需要在查询中使用PRIOR dt_from = dt_from，以确保生成的日期被视为行。如果不这样做，查询将在最后一个实际数据行处停止。AND PRIOR SYS_GUID() IS NOT NULL的引入是为了避免创建笛卡尔积。

CREATE TABLE date_period(dt_from DATE, dt_to DATE);

INSERT INTO date_period(dt_from, dt_to) VALUES (DATE '2023-02-13', DATE '2023-02-15');
INSERT INTO date_period(dt_from, dt_to) VALUES (DATE '2023-06-20', DATE '2023-06-22');

/*
Using a hierarchical query with the CONNECT BY clause 
to generate the dates between dt_from and dt_to for each row in the table. 
The PRIOR conditions used to prevent the query from generating a Cartesian product.
*/
SELECT dt_from + LEVEL - 1 AS dates
FROM date_period
CONNECT BY LEVEL <= dt_to - dt_from + 1
AND PRIOR dt_from = dt_from
AND PRIOR SYS_GUID() IS NOT NULL;

一种更“现代”和符合SQL标准的方法是采用“递归CTE”，而不是Oracle的专有语法。例如

/*
This recursive CTE generates the dates between dt_from and dt_to for each row in the table 
by repeatedly adding one day to dt_from until it is equal to dt_to.
*/
WITH date_range (dt_from, dt_to) AS (
  SELECT dt_from, dt_to FROM date_period
  UNION ALL
  SELECT dt_from + 1, dt_to FROM date_range WHERE dt_from < dt_to
)
SELECT dt_from AS dates FROM date_range ORDER BY dt_from;

fiddle

注意事项

我看不到任何东西可以阻止您的日期范围重叠，因此输出将重复日期。因此，为了避免这种情况，您可能需要在上述查询中采用SELECT DISTINCT。
fiddle with duplicates