title: sql query get all children and grandchildren
body: <p>What is proper way to get all children and grandchildren or n-generation children.
  for children and grandchildren my query is like below:</p>
  
  <pre><code>SELECT e1.ID, e1.LName + ', '+e1.FName
    FROM lstEmp e1  INNER JOIN lstEmp e2 ON e1.Supervisor = e2.ID
    Where e2.Supervisor = 'xxxxxxx'
   UNION 
    SELECT distinct e2.ID, e2.LName + ', '+e2.FName
    FROM lstEmp e1  INNER JOIN lstEmp e2 ON e1.Supervisor = e2.ID
    Where e2.Supervisor = 'xxxxxxx'
  </code></pre>
  
  <p>my question:1)is this the proper way?
  2) what if I need all children and grandchildren and (4,5..)n-generation children?</p>