title: How to update the 2nd and 3rd character in string with X
body: <p>I have an employee table with the columns first name and last name. I need to mask the data. I need to replace 2nd and 3rd character with X.</p>
  
  <pre><code>update employee 
  set last_name = 
  Stuff(last_name, CharIndex(LEFT(last_name,1), last_name), Len(LEFT(last_name,1)), 'X') 
  from Employee where Employee_Id = 'A.Abrahams'
  </code></pre>
  
  <p>The update is not working. Can any one help? Thanks in advance.</p>