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? 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, and every time an opinion is given, it should check if the tweet has already been reviewed by the logged in user. 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. 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. 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 :-) -- Posted via http://www.ruby-forum.com/.
Hi, Peter! I had the same problem (although completely unrelated to tweets). I did a has_many through pairs thing. Also, every 3 months I clean up the old stuff. Maybe someone knows a better solution? Cheers, Gleb -- Posted via http://www.ruby-forum.com/.
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 marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.
Hi So if I have a many-to-many database called pair, each entry will have a user_id and a tweed_id. This seems like it would be uselessly redundant if I can always search starting with a known user name. Wouldn''t it make sense to instead have a database with only one entry for each user, with (somehow) a corresponding array of tweets? Marnen Laibow-Koser wrote:> Peter Ehrlich wrote: ><snip> > > * You will definitely want foreign key constraints in the DB. Use the > foreign_key_migrations plugin.Why is this? It looks like a useful plugin indeed, but doesn''t rails already do some of this? In a totally unrelated area, I''m using strings as foreign keys. Is it possible (or a good idea) to do associations with them?> <snip> >> >> 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).So you would make the user records polymorphic - able to be both for existing users and anonymous ones? Couldn''t this just be done by having a database of users, with for anonymous users no name field (for example) and some kind of identifier instead. Thanks again, --Peter -- Posted via http://www.ruby-forum.com/.
Peter Ehrlich wrote:> Hi > > So if I have a many-to-many database called pair, each entry will have a > user_id and a tweed_id. This seems like it would be uselessly redundant > if I can always search starting with a known user name.It''s not redundant. Sure, you''ll always be searching starting with a known username, but then how will you find that user''s Pairs in the database if they don''t contain any info linking them to that user?> Wouldn''t it > make sense to instead have a databaseYou mean a table?> with only one entry for each user, > with (somehow) a corresponding array of tweets?No. That will contain the same information, but be much harder to query. [...]>> * You will definitely want foreign key constraints in the DB. Use the >> foreign_key_migrations plugin. > > Why is this? It looks like a useful plugin indeed, but doesn''t rails > already do some of this?No. Rails does not put foreign key constraints in the DB unless you use this plugin or something similar.> In a totally unrelated area, I''m using strings > as foreign keys. Is it possible (or a good idea) to do associations > with them?It''s possible, but Rails is usually happier with integer keys. [...]> So you would make the user records polymorphic - able to be both for > existing users and anonymous ones?That''s not what a polymorphic association is. Look it up. :)> Couldn''t this just be done by having > a databaseYou mean a table?> of users, with for anonymous users no name field (for > example) and some kind of identifier instead.Sure. I suggested the polymorphism because you may actually want to store different info for anonymous users.> > Thanks again, > --PeterBest, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.