Question

如何将行中的值检索为列值？

示例：

将以下查询的输出视为 INPUT ：

Select 1,2,3,4,5,6,7,8,9,10 
from dual;

我需要一个可以提供以下输出的查询：

Answer 1

SELECT 1 AS "COL1" FROM dual
UNION
SELECT 2 FROM dual
UNION
SELECT 3 FROM dual
UNION
SELECT 4 FROM dual
UNION
SELECT 5 FROM dual
UNION
SELECT 6 FROM dual
UNION
SELECT 7 FROM dual
UNION
SELECT 8 FROM dual
UNION
SELECT 9 FROM dual
UNION
SELECT 10 FROM dual ;

Answer 2

如果要在Oracle中生成一系列数字：

with n as (
      select level as n
      from dual
      connect by level <= 10 
     )
select *
from n;

或者，如果您有10列，则可以执行取消操作。一个简单的方法是union all：

select col1 from t union all
select col2 from t union al
. . .
select col10 from t;

选择值是一行作为列值

2 个答案: