product_sync.rb

# is it risky to trust on updated_at ?
# Summary: all products with no price on API should be disabled.

# adding a new 'updated_by_api_at' timestamp field to the products table...

start_time = Time.now
Product.transaction do
  ProductApi.each do |e|
    Product.find(e.code).update_attributes :price => e.price, :updated_by_api_at = Time.now
  end

  Product.update_all :status => :disabled, ['updated_by_api_at < ?', start_time]

end

# this should work, since updated_by_api_at would not be automatically updated by AR in other operations...