甲骨文：轉表

Question

我有以下查詢

SELECT 1, 2 FROM DUAL 

，我想是這樣

SELECT TRANSPOSE(SELECT 1, 2 FROM DUAL) 

至極輸出爲

SELECT 1 FROM DUAL 
UNION 
SELECT 2 FROM DUAL 

我會喜歡它與列交換行。

Answer 1

假設這是甲骨文11，可以使用UNPIVOT：

select no from 
(SELECT 1 a, 2 b FROM DUAL) dummy 
unpivot (no for col in (a as 'A', b as 'B')) 

Answer 2

如果你沒有的Oracle 11g，最好的辦法就是你提供的一個：

SELECT 1 FROM DUAL 
UNION 
SELECT 2 FROM DUAL