create_history.rb

task :history => :environment do
    item = Item.find(21064127)
    start_date =  item.updated.to_date - 90
    item.item_logs.delete_all
    90.times do |i|
      if i % 7 == 0
        item_log = ItemLog.new
        item_log.company_id = item.company_id
        item_log.item_id = item.id
        item_log.beforePrice = item.price
        item_log.afterprice = item.price
        item_log.created = start_date + i
        item_log.save
      end
    end
    item.competing_items.each do |competing_item|
      competing_item.item_logs.delete_all

      90.times do |i|
        if i % 7 == 0
          item_log = ItemLog.new
          item_log.company_id = competing_item.company_id
          item_log.item_id = competing_item.id
          item_log.beforePrice = competing_item.price
          item_log.afterprice = competing_item.price
          item_log.created = start_date + i
          item_log.save
        end
      end

    end
  end