如何为所选参数创建列？

Question

我有一个根据所选LOV参数获取结果的查询: nvl(:Role，role))

SELECT role,subject 
FROM HS_SUBJECT_INCIDENTS 
WHERE entitlement not in(select entitlement from HS_SUBJECT_INCIDENTS where role in nvl(:Role, role))
AND subject in (select subject from HS_SUBJECT_INCIDENTS where role in nvl(:Role, role))

因此，如果用户选择'Finance‘作为参数值，结果现在将显示：

|   Role    | Subject  | 
------------------------
| Marketing | Business |  
| Marketing | Business |  
| Analytics | Business | 

我希望结果如下所示：

|   Role    | Subject  | SelectedParameter |
--------------------------------------------
| Marketing | Business |  Finance          |
| Marketing | Business |  Finance          |
| Analytics | Business |  Finance          |

我必须在select语句中放入什么内容才能包含所选参数值的列？

Answer 1

只需选择它：

SELECT role, subject, :Role as SelectedParameter
FROM . . .