ActiveRecord and SQL Server (See related posts)

From http://www.softiesonrails.com/articles/2006/06/28/activerecord-with-sqlserver-without-rails:

Ensure you done the initial setup for SQL Server and ActiveRecord (ADO.rb).

require 'rubygems'
require_gem 'activerecord'

ActiveRecord::Base.establish_connection(
  :adapter  => "sqlserver",
  :dsn => "instance_name_goes_here",
  :host => "machine_name\\instance_name",
  :database =>  "db_name",
  :username =>  "my_username",
  :password =>  "my_password"
)

class MsSqlTable < ActiveRecord::Base
  def method_missing(method, *args)
    respond_to?(method) ? super : send(method.to_s.camelize, *args)
  end
end

class Item < MsSqlTable
  set_primary_key "sku"
  set_table_name "item"
end

I'll walk through it real quick:

1. The :dsn needs to be your SQL Server instance name
2. The :host needs to a path like "myserver\myinstance", even though you've already specified the instance name in the :dsn parameter
3. The rest of the settings should be obvious. If your password is blank, don't specify :password at all.
4. Our legacy column names are things like OldDescription. So I created an intermediate base class that would provide ruby-like aliases. Now I can use item.old_description instead if I want to.
5. Finally, I declare one class for each table I want to access. I have to set the primary key and table name manually, since our tables don't correspond to any Rails conventions.

I saved this script as legacy.rb, and then fired up irb from that directory:

irb> load 'legacy.rb'
=> true
irb> Item.find("191191").old_description
=> "Table In A Bag"
irb>