You could alway store them in known order so that sender.id <= reciver.id and use scoped validates_uniqueness_of.
Assuming that sender and reciver can be exchanged in this relationship and does not have any additional meaning. Like 'friendship' when it does not matter who is friend A and who is friend B Robert Pankowecki -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
