gistfile1.rb

# Ruby 1.9 compat for FasterCSV (painful)
# http://matthewbass.com/2008/01/05/csv-transmogrifies-into-fastercsv-in-ruby-19/
require 'csv'
if CSV.const_defined? :Reader
  require 'faster_csv'  # For CSV data files
else
  FasterCSV = CSV
end

namespace :db do
  # Adapted from http://erikonrails.snowedin.net/?p=212
  desc "Load all data from CSV files in RAILS_ROOT/db/seed_data"
  task :load_data => :environment do
    Dir["#{RAILS_ROOT}/db/seed_data/*.csv"].each do |f|
      # remove numeric ordering
      table_name  = File.basename(f, '.csv').sub(/^\d+_?/,'')
      # and _by_column_name which uses is configuration
      unique_key  = table_name.gsub!(/_by_(\w+)/,'') ? $1.to_s : nil
      model_class = table_name.to_s.singularize.camelize.constantize
      pk_name     = model_class.primary_key  # maybe 'id' or 'code' or ??
      unique_key  ||= pk_name
  
      # puts "primary_key(#{model_class}) = #{pk_name}"
      puts "-- loading data for #{table_name} from: #{f.sub(/.*(db\/)/,'\1')}"

      csv_rows = FasterCSV.read(f, :headers => true, :header_converters => :downcase)
      csv_rows.each do |row|
        attrib = row.to_hash
        pk_val = attrib[unique_key] || raise("CSV entry missing value for #{unique_key}: #{row}")
        record = model_class.find(pk_val) rescue nil
        if record
          # update
          attrib[:updated_at] = Time.now if record.respond_to?(:updated_at)
          record.update_attributes!(attrib)
        else
          record = model_class.new(attrib) # get new AR object
          # Use send to call pk attribute setter, eg, admin_account.id= or language.code=
          # These are protected in ActiveRecord so you must send() to them
          record.send("#{pk_name}=", pk_val) if pk_val
          record.created_at = Time.now if record.respond_to?(:created_at)
          record.updated_at = Time.now if record.respond_to?(:updated_at)
          record.save!
        end
      end
    end
  end
end