选择多行和双值中的一个值

Question

这很难解释，但我想在第一列中显示多行，在Oracle的第二列中显示一个相同的值，如下所示：

Select ('123', '456') First, 'abc' Second from dual;

我怎样才能做到这一点？

Answer 1

使用union all

Select '123' First, 'abc' Second from dual
union all
select '456','abc' from dual

Answer 2

使用union all

select '123', 'abc' from dual
 union all
select '456','abc' from dual

另一种类似方式

 select * from (select '123' as col1 from dual
 union all
 select '456' from dual) a, (select 'abc' as col2 from dual) b

COL1    COL2
123     abc
456     abc

演示

Answer 3

可能最短的语法是：

select column_value first, 'abc' second
  from table(sys.odcivarchar2list('123', '456', '789', 'A1', 'B70', 'C44'))

结果：

FIRST   SECOND
------  ------
123     abc
456     abc
789     abc
A1      abc
B70     abc
C44     abc

Answer 4

BAM！ 将20更改为所需的许多行。

select level as first, 'abc' as second
from dual
connect by level <= 20;