Based on your comment you could do the following:
os = OrderStatus.find(1)
os.translations.where(locale: "nl").first_or_create.update_attributes(status: "In aanmaak")
os.translations.where(locale: "en").first_or_create.update_attributes(status: "Creating")
I'm not sure if there's a nicer way of writing this, but you could create your own method:
class Translation < ActiveRecord::Base
def first_or_update(locale, status)
where(locale: locale).first_or_create.update_attributes(status: status)
end
end
os.translations.first_or_update("en", "Creating")