models.rb

# book.rb
require 'dm-is-list'

class Book
  include DataMapper::Resource

  property :id, Serial
  property :name, String, :nullable => false

  is :list

  has n, :chapters
end


# chapter.rb
class Chapter
  include DataMapper::Resource

  property :id, Serial
  property :number, Integer, :nullable => false

  belongs_to :book
  has n, :verses
end


# verse.rb
class Verse
  include DataMapper::Resource

  property :id, Serial
  property :text, Text, :nullable => false
  property :number, Integer, :nullable => false

  belongs_to :chapter
end

seeds.rb

require 'rubygems'
require 'datamapper'
require 'merb_datamapper'
require 'pp'
require 'app/models/book'
require 'app/models/chapter'
require 'app/models/verse'

merb_root = File.expand_path(File.dirname(__FILE__) / '../')

DataMapper.setup(:default, "sqlite3://#{merb_root}/sample_development.db")

B = Struct.new :position, :name, :chapters
C = Struct.new :number, :verses
V = Struct.new :number, :text

books = []

books << B.new(1, 'Genesis', [
  C.new(1, [
    V.new(1, 'In the beginning, God created the heavens and the earth.'),
    V.new(2, 'And the earth was without form and void, and darkness covered the face of the deep.')
  ]),
  C.new(2, [
    V.new(1, 'book 1, chapter 2, verse 1'),
    V.new(2, 'book 1, chapter 2, verse 2')
  ])
])

books << B.new(2, 'Exodus', [
  C.new(1, [
    V.new(1, 'Thou shalt love the Lord thy God.')
  ]),
  C.new(2, [
    V.new(1, 'book 2, chapter 2, verse 1'),
    V.new(2, 'book 2, chapter 2, verse 2')
  ]),
  C.new(3, [
    V.new(1, 'book 2, chapter 3, verse 1'),
    V.new(2, 'book 2, chapter 3, verse 2')
  ])
])

puts 'Inserting the following data:'
puts

books.each do |b|
  book = Book.new

  book.name = b.name
  book.position = b.position

  book.save

  puts "b.position => #{b.position}"
  pp book

  b.chapters.each do |c|
    chapter = Chapter.new

    chapter.book = book
    chapter.number = c.number

    chapter.save

    puts "c.number => #{c.number}"
    pp chapter

    c.verses.each do |v|
      verse = Verse.new

      verse.chapter = chapter
      verse.number = v.number
      verse.text = v.text

      verse.save

      puts "v.number => #{v.number}"
      pp verse
    end

    puts unless c.verses.last == c
  end

  puts unless books.last == b
end