How do I update a child db table when populating database in ruby on ralls?
namespace :db do
        desc "Create user records in the development database."
        task :populate => :environment do
          require 'faker'


          def randomDate(params={})
            years_back = params[:year_range] || 5
            latest_year  = params [:year_latest] || 0
            year = (rand * (years_back)).ceil + (Time.now.year - latest_year - years_back)
            month = (rand * 12).ceil
            day = (rand * 31).ceil
            series = [date = Time.local(year, month, day)]
            if params[:series]
              params[:series].each do |some_time_after|
                series << series.last + (rand * some_time_after).ceil
              end
              return series
            end
            date
          end

          def decimal_selection_array(start,limit,step_size=1)
            decimal_array = (start..limit).step(step_size).map{|i| i.to_s}.to_a
            decimal_array.insert(0,"Below #{start.to_f}")
            decimal_array.insert(-1,"Above #{limit.to_f}")
          end

          100.times do |n|
            username = "#{Faker::Name.first_name}#{n}"
            u = User.create!(
              :username => username,
              :email => Faker::Internet.email,
              :password => "foobar"
            )


            u.profile.update_attributes(
          :motd                => Faker::Lorem.words,

          #Profile details
          :first_name          => Faker::Name.first_name,
          :last_name           => Faker::Name.last_name,
          :birthday            => randomDate(:year_range => 60, :year_latest => 22),
          :gender              => (1..2).to_a.sample,
          :marital_status      => (1..7).to_a.sample,
          :sexual_preference   => (1..3).to_a.sample,
          :ethnicity           => (1..10).to_a.sample,
          :country             => Faker::Address.country,
          :location            => Faker::Address.country,

          #About the user
          :about_me            => Faker::Lorem.paragraph,

          #Personal stats
          :height              => decimal_selection_array(5.0,7.0,0.1).to_a.sample,
          :body_type           => (1..7).to_a.sample,
          :eye_colour          => (1..6).to_a.sample,
          :drugs               => (1..4).to_a.sample,
          :alcohol             => (1..4).to_a.sample,
          :cigarettes          => (1..3).to_a.sample,
          :likes               => Faker::Lorem.sentence,
          :dislikes            => Faker::Lorem.sentence,
          :bad_habits          => Faker::Lorem.sentence,

          #Favourite things
          :food                => Faker::Lorem.sentence,
          :music               => Faker::Lorem.sentence,
          :television          => Faker::Lorem.sentence,
          :book                => Faker::Lorem.sentence,
          :animal              => Faker::Lorem.sentence,
          :place               => Faker::Lorem.sentence,
          :possesion           => Faker::Lorem.sentence


            )





        end
      end
    end

before_safe :build_profile

# before running this task comment out: before_create :build_profile in user.rb in order to make this work correctly

namespace :db do
    desc "Create user records in the development database."
    task :populate => :environment do
      require 'faker'


      def randomDate
        "#{(1900..2012).to_a.sample}-#{(1..12).to_a.sample}-#{(1..28).to_a.sample}"
      end

      def decimal_selection_array(start,limit,step_size=1)
        decimal_array = (start..limit).step(step_size).map{|i| i.to_s}.to_a
        decimal_array.insert(0,"Below #{start.to_f}")
        decimal_array.insert(-1,"Above #{limit.to_f}")
      end

      1000.times do |n|
        username = "#{Faker::Name.first_name}#{n+1}"
        User.create!(
          :username => username.gsub(/[^0-9a-z]/i, ''),
          :email => Faker::Internet.email,
          :password => "foobar"
        )

        Profile.create!(
      :user_id             => "#{n+1}",
      :motd                => Faker::Lorem.sentence,

      #Profile details
      :first_name          => Faker::Name.first_name.gsub(/[^a-z]/i, ''),
      :last_name           => Faker::Name.last_name.gsub(/[^a-z]/i, ''),
      :birthday            => randomDate,
      :gender              => (1..2).to_a.sample,
      :marital_status      => (1..7).to_a.sample,
      :sexual_preference   => (1..3).to_a.sample,
      :ethnicity           => (1..10).to_a.sample,
      :country             => Faker::Address.country,
      :location            => Faker::Address.country,

      #About the user
      :about_me            => Faker::Lorem.paragraph,

      #Personal stats
      :height              => decimal_selection_array(5.0,7.0,0.1).to_a.sample,
      :body_type           => (1..7).to_a.sample,
      :hair                => (1..7).to_a.sample,
      :eye_colour          => (1..6).to_a.sample,
      :drugs               => (1..4).to_a.sample,
      :alcohol             => (1..4).to_a.sample,
      :cigarettes          => (1..3).to_a.sample,
      :likes               => Faker::Lorem.sentence,
      :dislikes            => Faker::Lorem.sentence,
      :bad_habits          => Faker::Lorem.sentence,

      #Favourite things
      :food                => Faker::Lorem.sentence,
      :sport               => Faker::Lorem.sentence,
      :music               => Faker::Lorem.sentence,
      :television          => Faker::Lorem.sentence,
      :book                => Faker::Lorem.sentence,
      :animal              => Faker::Lorem.sentence,
      :place               => Faker::Lorem.sentence,
      :possession          => Faker::Lorem.sentence


        )


    end
  end
end