Simple Association

Hello, I am new to rails and I need a little help getting started with
a simple association. Here is what I am trying to do.

I have a model, message, which has text and a user (do not need to
worry about associating users to messages right now). These messages
come in and I would like to create a response for each, which itself
is a message. Then I would like to create a transaction paring these
responses and requests.

@request = Message.create(:text => "Some text")
@response = Message.create(:text => "Some text back")
@some_transaction = Transaction.create(:request =>
@request.id, :response => @response.id)

From there I would like to be able to sort through each transaction:
@some_transaction.request.text

How are these associations formed? When generating the models do I
need to have columns for request/response or request_id/response_id?

Thanks for any help!

Here's a good place to start reading:

http://guides.rubyonrails.org/association_basics.html

Some other notes:

- 'Transaction' is not going to work as a model name; ActiveRecord
uses that name internally, and redefining it may cause extremely
peculiar malfunctions.

- if messages are paired strictly one-to-one with replies, it may make
more sense to omit the intermediate model entirely and just define a
has_one/belongs_to pair.

--Matt Jones