tinytds_repl.rb

#!/usr/bin/env ruby

RAILS_ROOT = File.expand_path '../..', __FILE__
require "rubygems"
require "yaml"
require "tiny_tds"
require "singleton"

class Connection
  include Singleton

  def initialize
    @client = TinyTds::Client.new config
  end

  def query sql
    @client.execute sql
  end

  private

  def config
    hash = YAML.load(File.read("#{RAILS_ROOT}/config/e21.yml"))
    hash.keys.each do |key|
      hash[key.to_sym] = hash.delete(key)
    end
    hash
  end
end

class Repl
  include Singleton

  def initialize
    @connection = Connection.instance
  end

  def process input
    result = @connection.query input
    result.each { |row| output row }
    result.cancel
  end

  def output row
    puts row
  end

end

# let's run it
loop do
  print "e21> "
  Repl.instance.process gets.chomp!
end