Try

SELECT *
  FROM vw.foo  f
  WHERE f.cost_center LIKE 
    CASE WHEN @cost_center = 'ALL' THEN '%' ELSE @cost_center END 

>After two years I am back doing SQL Server, I don't mind.
>
>
>My first asignment is to create a report for one of the cost centers or two of the cost centers depending on if 'ALL','SMS', or 'SMP' is inputed by the user.
>
>I made a view with just 'SMS' and 'SMP' in it.
>
>What is the best way to handle this, I have been using brute force i.e.
>
>
>if @cost_center = 'ALL'
>
>Begin
>SELECT *
>FROM vw.foo f
>END
>
>ELSE
>
>BEGIN
>
>SELECT *
>FROM vw.foo f
>WHERE f.cost_center = @cost_center
>
>END
>
>Is there a better way?