ActiveRecordでSQLServerへ接続する ref: http://qiita.com/items/43848e4246fbe513cf4c

file0.txt

source "https://rubygems.org"

gem 'tiny_tds'
gem 'activerecord-sqlserver-adapter'
gem 'arel', '~> 3.0.2'
gem "tap"
gem "ruby-odbc"
gem "dbi"
gem "dbd-odbc"
gem "logger"

file1.txt

bundle install --path .bundle

file2.yml

development:
  adapter: "sqlserver"
  mode: "odbc"
  host: "localhost"
  username: "mssql_user"
  password: "mssql_password"
  database: "database name"
  dataserver: "Server name"
  dsn: "mssql dsn"  # 「コントロールパネル」 => 「ODBCデータソースアドミニストレータ」 で接続先のDBへのDSNを作成します。

file3.txt

# coding:utf-8
require "rubygems"
require "activerecord-sqlserver-adapter"
require "odbc"
require "yaml"
require "logger"

@setting = YAML::load(File.open("database.yml"))["development"]
ActiveRecord::Base.logger = Logger.new("debug.txt")

ActiveRecord::Base.establish_connection(
  adapter: @setting["adapter"],
  mode: @setting["mode"],
  host: @setting["host"],
  username: @setting["username"],
  password: @setting["password"],
  database: @setting["database"],
  dataserver: @setting["dataserver"],
  dsn: @setting["dsn"]
  )

class User < ActiveRecord::Base
  self.table_name = "user_table" 　#接続したDBのテーブル名は「user_table」となっており、ActiveRecordの命名規則に反していたためtable_name にて設定
end