oracle返回多行常量串(写死)的值

有个兄弟非要在sql中返回月份01,02....

我想到下面2个办法

1.使用union

select '01' from dual union

select '02' from dual union

......

2.使用regexp_substr函数

select regexp_substr('01,02,03,04,05,06,07,08,09,10,11,12','[^,]+',1,rownum) from dual  connect by rownum<=12

标准的格式应该是
select regexp_substr('01,02,03,04,05,06,07,08,09,10,11,12','[^,]+',1,rownum) from dual
connect by rownum<=length('01,02,03,04,05,06,07,08,09,10,11,12')-length(replace('01,02,03,04,05,06,07,08,09,10,11,12',','))+1

但是把长度计算一下就没有必要写那么长了。

比如 select regexp_substr('红色,白色,黑','[^,]+',1,rownum) from dual connect by rownum<=3