On Sat, Mar 5, 2011 at 4:13 PM, Alexey M. <[email protected]> wrote:
> Hello, I am re-opening this again, sorry :). > > I have just read in RailsGuides ( > http://guides.rubyonrails.org/association_basics.html ) > about the proper way to choose between belongs_to and has_one. > From this point of view, something like belongs_to_many seems to be > really missing, but i do not know if maybe there is a better name, and > how to call the other side of the association (has_a ?). > I am talking about something like this: > > class Member < ActiveRecord::Base > has_an :address > end > > class Address < ActiveRecord::Base > belongs_to_many :members > end > > Different members can have the same address, if they are a couple for > example. > > This can me implemented the same way as has_and_belongs_to_many, except > that in the joint table the Foreign Key for Members must be required to > be unique. > > An Address can be then automatically deleted when the last Member living > at that address is deleted. > > The advantage over [belongs_to, has_many] is the same as for has_one > over belongs_to: the Members table does not need to "know" about the > Addresses table. > The thing is, this would just duplicate existing associations; I don't see how it's needed. The relationship you describe above can be written much simpler (no join table at all) by just having User belongs_to :address, and Address has_many :users. If it's the readability of the code that you want, you can always do things like class Address << ActiveRecord::Base has_many :residents, :class_name => "User" end class User << ActiveRecord::Base belongs_to :address, :foreign_key => "resident_id" end For many-to-many, I really tend to favor has_many :through associations from both sides, as they're more flexible. But honestly; I don't think belongs_to_many is missing. Just my 2ยข. :-) > -- > 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. > > -- 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.
