Help me on Triggers ?

Question

I want to write a trigger on view which depends on tables emp.
emp
empno
name
dept
desig
dob
basic
hra
da
create or replace view empview
as
select * from emp;
1) Will to insert bulk of records to the view as
insert into empview select * from emplot where dept = 'sales';
2) Delete records which are not available in emp table,insert new records into emp, update existing records

Answer 1

I found there is no other way than trigger. But let me know any other suggestion
Constraints are
1) Should not delete all records in emp and reinsert, because it is linked in a front-end. If we delete all, it will affect remote users who are looking at it
2) if record exists in emp table Insert/update one by one record in emp
3) records non exist in emplot and exists in emp table should be removed.
4) Emplot contains blob data and extraction is using different way.
Please let me know whether we can
Compare data’s in emp table with the incoming data’s and finally remove non available from emp?
We will get the data to emp table exactly as below
insert into empview select * from table(extract_data(emplot,’sales’));