title: Exclude active record set from another recordset?
body: <p>Is there a way to exclude the results of recordset #1 from recordset #2 in Rails 3 or 4, Activerecord?</p>
  
  <p>I have tried this before with ugly code trying to remove the id's by adding them to a hash and excluding them from the query. </p>
  
  <p>Must be a clean way to remove certain id's or results from a recordset?</p>