2 different databases in 1 application? MySQL & Informix

Quick google search turned up this:

http://wiki.rubyonrails.org/rails/pages/HowtoUseMultipleDatabases

Mary Nu wrote:

Hi Mary,

I've got one similar project where I perform some queries on a legacy
MS SQL database and use a (new) My SQL database to manage the newer
part of the system. It is possible and it works OK. I had to go
through a few nightmares with MS SQL / RoR (bugs in the adapter,
problems with specific field types, problems with pagination, etc),
but I got it to do what I need.

The way I'm doing it is pretty simple, no plug-in, all based on pure
rails. This is how:

1) in you models pointing to the legacy database, you might need to
specify table names and primary key columns as they probably wont
follow RoR default naming conventions:

class Consultants < External
  set_table_name "Consultants"
  id = "ConsIntID"

     .....
end

You can also see that I'm deriving Consultants from "External". This
is how the External model looks like:

class External < ActiveRecord::Base
  self.abstract_class = true
  establish_connection :yourlegacydb
end

Then you can have any model pointing to the legacy DB derived from
External, and you can configure your connection to your legacy db in
your database.yml file just like this:

yourlegacydb:
  adapter : ...
  ..

Good luck,
Seb