SQL & PL/SQL :: Primary Key On A View

While making a view.

1. Is it advisable to have primary key in a view.

2. Why can't we have a primary key in a view, what are its advantages. I mean one cannot search a view by index.

3. Is it because of hibernate, but again i have used distinct keyword in a view declaration which means i cannot insert via view.

Here is my code for view to make a primary key in a view.

CREATE OR REPLACE FORCE VIEW VU_NAME
PRIMARY_KEY, NAME_ID, ADDRESS_ID
)

[Code]....

alter view VU_NAME add constraint vemp_pk primary key (PRIMARY_KEY) disable