Access rights, best approach?

Question

One of our business rules restricts updates on 3 fields in a table for one type of user, and 5 fields in that same table to another type of user. I could use 2 views to implement these restrictions, but is there another approach? I'd like to create a single Oracle Form for all users, and avoid the complexity of conditionally using one of many views during UPDATE.
With object privileges, is there a way to restrict UPDATE/INSERT/DELETE on particular columns in a table, while not restricting other columns, without the use of views?
-Thanks
cf

Answer 1

An extension of this question:
We have a user which is allowed to insert a record into a table, but can only create data in 5 of 10 available fields, but we want default values inserted into the 'unavailable' fields.
I tried to test this out by starting with the following, but I couldn't get data to load:
SQL> create table chuck
2 (myname varchar2(10),
3 age number default 26);
Table created.
SQL> insert into chuck values ('Chuck');
insert into chuck values ('Chuck')
ERROR at line 1:
ORA-00947: not enough values
SQL> insert into facet.chuck values ('Chuck',1)
1 row created.
I wouldn't ask if I could figure out how to test the concept myself.
-Chuck