在oracle查询中选择行值作为列

Question

这是表：

select * from ABCD;

|    ABCD_ID | ROLE  | NAME | PARAM   | VALUE |
+============+=======+======+=========+=======+
|    1       | Allow | A1   | Period1 | 1     |
|    1       | Allow | A1   | Period1 | 2     |
|    1       | Allow | A1   | Period1 | 3     |
|    2       | Allow | A2   | Period2 | 11    |
|    2       | Allow | A2   | Period2 | 12    |
|    3       | Allow | A3   | Period3 | 111   |
|    4       | Allow | A4   | XY      | 200   |

我想运行select查询将句点作为列，列的值将为“VALUE”

需要输出：

|    ABCD_ID   | ROLE  | NAME | Period |
+==============+=======+======+========+
|            1 | Allow | A1   | 1      |
|            1 | Allow | A1   | 2      |
|            1 | Allow | A1   | 3      |
|            2 | Allow | A2   | 11     |
|            2 | Allow | A2   | 12     |
|            3 | Allow | A3   | 111    |

查询我尝试过：

select ABCD_ID,role,name,param, 
       (select distinct value 
        from ABCD 
        where ABCD_ID=a.ABCD_ID 
          and param like '%Period%') as "Period" 
from ABCD a 
where role='Allow' 
  and param like '%Period%'

获取此错误：ORA-01427：单行子查询返回多行

Answer 1

看起来像一个简单的列别名给我：

select ABCD_ID,
       role,
       name,
       value as "Period"
from ABCD a 
where role='Allow' 
  and param like 'Period%'

Answer 2

我不认为你需要添加'role ='允许'的条件。

从ABCD a中选择ABCD_ID，角色，名称，值作为“期间”，其中参数如'Period％'