How to add a default constraint on existing column which applies to existing data in oracle
<p>I have following table with data</p>

<pre><code>create table emp_status(
    empno number,
    status varchar2(10)
    );
insert into emp_status values(100,null);
insert into emp_status values(200,null);
alter table emp_status modify status default 'Active';

select * from emp_status;
    empno status
    100   null
    200   null
</code></pre>

<p>I don't see the default values like 'Active' for above records.</p>