gistfile1.rb

namespace :associate_users do
  desc "Update users external builder" do
    @users = User.where(:external_builder_id => nil)
    @users.each do |user|
      #associate ExternalBuilder with User
      unless user.lbp_number.blank?
        @builder = ExternalBuilder.where(:lbp_number => user.lbp_number.gsub("BP", "").to_i)
        if !@builder.blank?
          u.update_column(:external_builder_id, @builder)
        end
      end
    end
  end
end