gistfile1.rb

class Card < ActiveRecord::Base
  set_table_name "card"
  has_many :messages, :class_name => "MsgQueue"
end

class MsgQueue < ActiveRecord::Base
  self.table_name = "msg_queue"
  belongs_to :card
  belongs_to :templates
end

irb(main):001:0> msg = Card.first
=> #<Card id: 1, passport: nil, first_name: "xxxx", last_name: "yyy", email: "[email protected]", phone: "****", mobile: "***", street: nil, city: nil, zip: nil, active: true, comment: "", created_at: "2012-11-15 07:05:08", updated_at:
 "2012-11-15 07:05:08">
irb(main):002:0> msg.messages
  ←[1m←[36mMsgQueue Load (1.0ms)←[0m ←[1mSELECT `msg_queue`.* FROM `msg_queue` WHERE `msg_queue`.`card_id` = 1←[0m
Mysql2::Error: Unknown column 'msg_queue.card_id' in 'where clause': SELECT `msg_queue`.* FROM `msg_queue` WHERE `msg_queue`.`card_id` = 1