db:dump_data and db:load_data

db.rake

#largely based on http://devblog.michaelgalero.com/2008/11/03/custom-rake-tasks-in-merb-data-import/

require 'rake'

ENV['ENVIRONMENT'] = 'test' if ENV['ENVIRONMENT'].nil?

# DB tasks
namespace :db do
  require 'dm-core'
  require 'dm-types'
  require 'dm-timestamps'
  require 'dm-constraints'
  require 'dm-validations'
  require 'dm-migrations'
  require 'dm-serializer'
  
  desc "Dump data from the current environment's DB."
  task :dump_data do
    #NOTE: Decimals in your models do not dump!!! I changed mine to Float for this purpose
    dir = "/Users/irio/Code/MyTraining/dev/db" #Change to suit
    FileUtils.mkdir_p(dir)
    FileUtils.chdir(dir)
    boot_repository
    DataMapper::Model.descendants.entries.each do |table|
      puts "Dumping #{table}..."
      File.open("#{table}.yml", 'w+') { |f| f.print table.all.to_yaml }
    end
  end

  desc "Load data (from spec/db/*.yml) into the current environment's DB."
  task :load_data do
    dir = "/Users/irio/Code/MyTraining/spec/db"
    FileUtils.chdir(dir)
    boot_repository
    DataMapper::Model.descendants.entries.each do |table|
      yaml_file = "#{dir}/#{table}.yml"
      if File.exists?(yaml_file)
        puts "Loading #{table} data..."
        YAML.load_file(yaml_file).each do |fixture|
          table.create( fixture )
        end
      end
    end
  end

  def boot_repository
    DataMapper.setup(:default, 'postgres://elland:elland@127.0.0.1/my_training_dev')
    Dir["/Users/irio/Code/MyTraining/app/models/*.rb"].each { |model| require model }
    DataMapper.finalize if DataMapper.respond_to?(:finalize)
    DataMapper.auto_migrate! # Destructively recreates all tables and indexes
  end
end