count

# File activerecord/lib/active_record/associations/has_many_through_association.rb, line 34
      def count(*args)
        column_name, options = @reflection.klass.send(:construct_count_options_from_args, *args)
        if @reflection.options[:uniq]
          # This is needed because 'SELECT count(DISTINCT *)..' is not valid SQL statement.
          column_name = "#{@reflection.quoted_table_name}.#{@reflection.klass.primary_key}" if column_name == :all
          options.merge!(:distinct => true) 
        end
        @reflection.klass.send(:with_scope, construct_scope) { @reflection.klass.count(column_name, options) } 
      end