单个SQL查询应显示sysdates如下

Question

需要输出

Sysdate
Sysdate+1
Sysdate+2
Sysdate+3

它应该类似于以下查询的输出，

SELECT SYSDATE FROM DUAL

UNION

SELECT SYSDATE+1 FROM DUAL

UNION

. . .

. . .

so on,

但不应使用UNION，帮助。

Answer 1

您可以使用CONNECT BY：

SELECT SYSDATE + LEVEL - 1
FROM   DUAL
CONNECT BY LEVEL <= 4;

或者您可以使用公用表表达式

WITH CTE( "Date", lvl ) AS
(
  SELECT SYSDATE, 1 FROM DUAL
  UNION ALL
  SELECT SYSDATE + lvl, lvl + 1 FROM CTE WHERE lvl <= 3
)
SELECT "Date" FROM CTE;