SQL Server - update only when values are different

Question

In SQL Server 2008, how do I update fields in a table only if their values differ with the values in the update statement ?

For example:

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'.

TIA

Answer 1

update TableA 
set FirstName = 'Roger Moore' 
where ID = '007' 
    and FirstName <> 'Roger Moore'