Oracle Query 基于数据到水平 [重复]

Question

我想查询以下这些数据样本。 （甲骨文数据库）

表名：FL_TEST

NAMA    JAM  STATUS
A       2    P
A       1    O
A       3    O
B       1    O
B       2    P
B       3    O
C       1    O
C       2    P
C       3    P

变成这样：

NAMA    JAM1 JAM2 JAM3
A       O    P    O
B       O    P    O
C       O    P    P

是否可以进行该查询？

Answer 1

使用条件聚合

select NAMA ,max(case when jam=1 then status end) as jam1,
max(case when jam=2 then status end) as jam2,
max(case when jam=3 then status end) as jam3
from FL_TEST group by NAMA

或者你可以使用枢轴

SELECT *
  FROM FL_TEST
PIVOT (
  MAX(status) as JAM FOR jam IN (1,2,3)
 );

Answer 2

你可以使用Conditional Aggregation：

select nama, 
       max( case when jam = 1 then status end ) as jam1,
       max( case when jam = 2 then status end ) as jam2,
       max( case when jam = 3 then status end ) as jam3
  from tab
 group by nama

或pivot：

select * 
  from tab
 pivot(
       max(value) for field in ( 1 as "Jam1", 
                                 2 as "Jam2",
                                 3 as "Jam3" ) )

Demo