title: How do I change my sql statement WHERE clause based on drop down selection
body: <p>I know this is a newbie question but I need to know how to dynamically change the WHERE clause in a SQL statement based on a drop down selection.</p>
  
  <p>I have a list of supervisors in a drop down.  I know how to use each one individually using the parameter, but how do I change the SQL when they select the ALL option?</p>