gistfile1.rb

  scope :has_all_items_in_state, lambda {|item_states|
    {
      :joins => :order_items, :conditions => { :order_items => { :state => item_states}},
      :select => "orders.*, COUNT(order_items.id) as item_count",
      :group => "orders.id",
      :having => "item_count = (select count(*) from order_items where order_id = orders.id)"
    }
  }