sql - Rails: Get next / previous record

Question

My app has Photos that belong to Users.

In a photo#show view I'd like to show "More from this user", and show a next and previous photo from that user. I would be fine with these being the next/previous photo in id order or the next/previous photo in created_at order.

How would you write that kind of query for one next / previous photo, or for multiple next / previous photos?

Answer 1

Try this:

class User
  has_many :photos
end


class Photo
  belongs_to :user

  def next
    user.photos.where("id > ?", id).first
  end

  def prev
    user.photos.where("id < ?", id).last
  end

end

Now you can:

photo.next
photo.prev