tron wrote: > class Word > end > > class PhraseComponent > belongs_to :word > belongs_to :dictionary_entry > acts_as_list :scope => :dictionary_entry > end > > class DictionaryEntry > has_many :phrase_components > has_many :words, :through => :phrase_components > end >
Well from the database side of thing that's easily solved by adding a unique index across the two foreign keys in the join table. That would definitely prevent duplicates in the join table. CREATE UNIQUE INDEX idx_word_dictionary_entry ON phrase_components (word_id, dictionary_entry_id); >From the Rails side you might be able to use something like the following example: class TeacherSchedule < ActiveRecord::Base validates_uniqueness_of :teacher_id, :scope => [:semester_id, :class_id] end Maybe (untested): class PhraseComponent < ActiveRecord::Base validates_uniqueness_of :word_id, :scope => :dictionary_entry validates_uniqueness_of :dictionary_entry_id, :scope => :word_id end Note: This may be an expensive method for validating uniqueness! In any of the cases mentioned you'll still have issues related to "Optimistic Concurrency Control:" http://en.wikipedia.org/wiki/Optimistic_concurrency_control This section of the Rails documentation has a good explanation of these issues and some options on how to solve them: http://www.railsbrain.com/api/rails-2.2.2/doc/index.html?a=M001824&name=validates_uniqueness_of -- 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 [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 -~----------~----~----~----~------~----~------~--~---
