0

这是示例:

ID | value
1     51
2     25
3     11
4     27
5     21

我需要获取前三个参数并将它们放入变量中,例如 out_x、out_y、out_z。是否可以在没有多项选择的情况下做到这一点?

4

2 回答 2

0

您可以使用PIVOT

SELECT x, y, z
INTO   out_x, out_y, out_z
FROM   your_table
PIVOT  ( MAX( value ) FOR id IN ( 1 AS x, 2 AS y, 3 AS z ) )

或者,如果您不知道ID需要哪个 s(但只想要前 3 个),那么:

SELECT x, y, z
INTO   out_x, out_y, out_z
FROM   (
         SELECT value, ROWNUM AS rn
         FROM ( SELECT value FROM your_table ORDER BY id )
         WHERE  ROWNUM <= 3
       )
PIVOT  ( MAX( value ) FOR rn IN ( 1 AS x, 2 AS y, 3 AS z ) )
于 2017-04-25T11:41:41.113 回答
0

你可以这样做:

select max(case when id = 1 then value end),
       max(case when id = 2 then value end),
       max(case when id = 3 then value end)
into out_x, out_y, out_z
from t
where id in (1, 2, 3);

但是,我认为表单的三个查询:

select value into out_x
from t
where id = 1;

是一种更清洁的方法。

于 2017-04-25T11:25:01.243 回答