title: Oracle 12c - select rows with multiple values in a group
body: <pre><code>select ssn, count(*) 
  from (
    select ssn, employee_id, is_active 
    from employee 
    where is_active ='Y'
  )
  group by ssn
  having count(*) &gt; 1
  </code></pre>
  
  <p>I want to modify this query to find all <code>ssn</code>'s that exist in the table more than once BUT with different <code>employee_id</code>'s, with at least one record having <code>is_active</code> of Y.</p>