SQL> ed
Wrote file afiedt.buf

  1  create or replace trigger tr_instead
  2  instead of insert or update or delete on v_complex
  3  begin
  4   if inserting then
  5    insert into emp(ename, empno, deptno)
  6      values(:new.ename, :new.empno, :new.deptno);
  7    insert into dept(deptno, dname)
  8      values(:new.deptno, :new.dname);
  9   elsif deleting then
 10      delete from emp
 11       where empno=:old.empno;
 12     delete from dept
 13      where deptno=:old.deptno;
 14   elsif updating then
 15     update emp set ename=:new.ename, deptno=:new.deptno
 16       where empno=:old.empno;
 17    end if;
 18* end;
SQL> /

Trigger created.

SQL> ed
Wrote file afiedt.buf

  1  create view v_complex as
  2  select d.deptno, e.ename, e.empno, d.dname
  3   from emp e, dept d
  4* where d.deptno=e.deptno
SQL> /

View created.

SQL> ed
Wrote file afiedt.buf

  1  insert into v_complex(d.deptno, e.ename, e.empno, d.dept)
  2*  values(10, 'sherya', 7668, 'design')
SQL> /
insert into v_complex(d.deptno, e.ename, e.empno, d.dept)
                                                    *
ERROR at line 1:
ORA-00904: invalid column name

insert into v_complex
  (deptno, ename, empno, dname)
   values
  (10, 'sherya', 7668, 'design')