http://www.imjo.hn/archive/using-datamapper-with-sinatra

database.rb

require "dm-core"
require "dm-migrations"

# Configure DataMapper
DataMapper.setup(:default, ENV['DATABASE_URL'] || "sqlite3://database.db")

# model Article
class Article
  include DataMapper::Resource
  
  property :id, Serial
  
  property :title, Text
  property :text, Text
  property :author, String
  property :permalink, Text
  property :created_at, DateTime
  
end

# Update database
DataMapper.auto_upgrade!

class String
  # Fix DataMapper's weird space bug
  def rm_ln
    self.gsub(/\n\n|\n/, "\r")
  end
  def rm_ln!
    self.gsub(/\n\n|\n/, "")
  end
end