scopes related question

Hello, Have a question related scope definition. I need to define a scope based on related model attribute values like this.

class Product < ActiveRecord::Base    belongs_to :currency

scope :with_currency, lambda { |currency|     unless currency.to_s.upcase == 'ALL'

# here I need to define a scope that would test for currency.char_code to match a passed value # something like.. This is where I need help       where("currency.char_code = ?", currency.to_s.upcase)     end   }

end

class Currency < ActiveRecord::Base attr_accessor : char_code end

class LineItem < ActiveRecord::Base     belongs_to :product

   scope :with_currency, lambda { |currency|     unless currency.to_s.upcase == 'ALL'

# here is another scope where I need help..       where("product.currency.char_code = ?", currency.to_s.upcase)     end   }

end

Thanks for suggestions. Still learning the scoping magic.

figured out the answer to this problem. I needed to use :joins to include associated models in scopes.