Peter Ehrlich wrote: > Hi > > I have website which displays tweets (from twitter). Each tweet can > either be given thumbsup or thumbsdown, but only once. What would be > the best way to organzine a database table for this? Its a many-to-many > relationship between tweets and users - should I make a database, lets > call it 'pairs', so that each user will have_many :tweets through pairs?
You will need a join table -- it's impossible to do many-to-many relationships without it. You can call it "pairs", though I might use "ratings". Then: class User has_many :pairs has_many :tweets, :through => :pairs end class Tweet has_many :pairs has_many :users, :through => :pairs end class Pair belongs_to :tweet belongs_to :user end Notes: * You may not need the has_many :through associations at all. * You might want to give the associations different names than the tables. * You will definitely want foreign key constraints in the DB. Use the foreign_key_migrations plugin. > I should have validation coming from two directions - when displaying > the tweet, it should check if the logged in user has already given the > tweet thumbsup/thumbsdown, current_user.tweet_ids.include? @tweet.id > and every time an opinion is given, it should > check if the tweet has already been reviewed by the logged in user. This is best done with DB constraints. > > I could see this database of pairs becoming very large, but fortunately > there's really no reason to let users rate tweets after a certain date - > so I could make a periodic job that removes old entries from the table > after a week or so. No, because then you'd lose your rating data. > > I'm sure that I could work out a solution on my own, but this is > somewhere I'd much rather be sure that I'm doing the right way, rather > than having to go back an change it later for performance or > maintainability reasons. Understood. > Thanks in advance for any input! > > Cheers, > --Peter > > PS - It would be nice to allow users without accounts to rate tweets. I > could store pair data in their session, but this would obviously not be > bulletproof. One big concern is if robots take advantage, rating 1000s > of times by clearing their sessions and such. Will be googling on this > :-) Then you'll need a way to identify anonymous users and make User records for them (or use a polymorphic association). Best, -- Marnen Laibow-Koser http://www.marnen.org mar...@marnen.org -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk@googlegroups.com To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
