title: SQL Server - update only when values are different
body: <p>In SQL Server 2008, how do I update fields in a table only if their values differ with the values in the update statement ?</p>
  
  <p>For example: </p>
  
  <p>I have TableA with column FirstName whose value is 'Roger Moore' with an unique id of '007'. 
  Now, i am calling an update statement but it should update the 'FirstName' field only if value is something else other than 'Roger Moore'.</p>
  
  <p>TIA</p>