I use the PostgreSQL database with Sequel. I have the following data in my table: table.all returns following data:
  [{:id=>1,
  :identifier=>"identifier",
  :first_name=>"First",
  :middle_name=>"M.",
  :last_name=>"Last 2",
  :email=>"some@email.com"},
 {:id=>2,
  :identifier=>"identifier",
  :first_name=>"First 2",
  :middle_name=>"A.",
  :last_name=>"Last2 ",
  :email=>"some@email2.com"}]
Now I want to find ids of record which identifier belongs to more than one first_name - last_name combination. So in this example we have two records with the same identifier but different first and last names. Is there any way to do this in Sequel?
