app/models/acl.rb

   1 class Acl < ActiveRecord::Base
   2   scope :address, lambda { |address| where("#{inet_aton} & netmask = address", address) }
   3
   4 private
   5
   6   def self.inet_aton
   7     if self.connection.adapter_name == "MySQL"
   8       "inet_aton(?)"
   9     else
  10       "?"
  11     end
  12   end
  13 end