Updateable View Issue

Question

I am trying to create a view to hide a specific column if the row is a certain type. My view works really well for selecting but, because of the decode function in the select statement, I cannot update that "virtual" column.
As I am trying to fool a package I have limited options open to me. I really need one view that will allow updates to this column if the row isn't of the restricted type.
My view....
CREATE OR REPLACE FORCE VIEW SECURE.F0101
(ABAN8, ABALKY, ABTAX)
AS
select ABAN8 ,
ABALKY ,
decode (abat1, 'E ', ' ', ABTAX) ABTAX,
from testdta.f0101
If you have any suggestions, I would appreciate it.

Answer 1

Create 'instead of' triggers on the view, as in this example:
SQL> create or replace view v_emp as
  2  select empno, decode(ename,'SMITH','SMYTH', ename) ename from emp;
View created.
SQL> update v_emp
  2  set ename='JACKSON'
  3  where empno=7499;
set ename='JACKSON'
ERROR at line 2:
ORA-01733: virtual column not allowed here
SQL> create or replace trigger v_emp_update
  2     instead of update on v_emp
  3   begin
  4     update emp
  5     set    ename = :new.ename
  6     where  empno = :new.empno;
  7   end;
  8  /
Trigger created.
SQL> update v_emp
  2  set ename='JACKSON'
  3  where empno=7499;
1 row updated.
SQL> commit;
Commit complete.
SQL> select * from v_emp
  2  where empno=7499;
     EMPNO ENAME
      7499 JACKSON