Hi all, I have a question about how utilizing has_many. I wrote the code without an editor & testing, so it could contain some errors. Oh, and also don''t mind the weird parent/child relationships here :) http://pastie.caboo.se/139456 I want to be able to do something like: Parent.find(:first).children[0].active How can I achieve this? With has_and_belongs_to_many this was easy. But I was fiddling with has_many and I could not get it working like this. What am I doing wrong? Thanks in advance! -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Why do you say HABTM is deprecated? Just curious. I was always under the impression you use HABTM if you just want a simple relationship with no extra information and the :through option if you needed a more complex setup. -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Nathan Esquenazi wrote:> Why do you say HABTM is deprecated? Just curious. I was always under the > impression you use HABTM if you just want a simple relationship with no > extra information and the :through option if you needed a more complex > setup.I read this in trac: DEPRECATED: Using additional attributes on has_and_belongs_to_many associations. Instead upgrade your association to be a real join model [DHH] http://dev.rubyonrails.org/changeset/4123 -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On 1/16/08, Leon Bogaert <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > Nathan Esquenazi wrote: > > Why do you say HABTM is deprecated? Just curious. I was always under the > > impression you use HABTM if you just want a simple relationship with no > > extra information and the :through option if you needed a more complex > > setup. > > I read this in trac: > DEPRECATED: Using additional attributes on has_and_belongs_to_many > associations. Instead upgrade your association to be a real join model > [DHH]If you read that again and highlight the key phrase: DEPRECATED: USING ADDITIONAL ATTRIBUTES on has_and_belongs_to_many associations. Instead upgrade your association to be a real join model As Nathan said, using habtm to represent a simple many-to-many relationship is not deprecated. -- Rick DeNatale My blog on Ruby http://talklikeaduck.denhaven2.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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Rick Denatale wrote:> On 1/16/08, Leon Bogaert <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote: >> [DHH] > If you read that again and highlight the key phrase: > > DEPRECATED: USING ADDITIONAL ATTRIBUTES on has_and_belongs_to_many > associations. Instead upgrade your association to be a real join model > > As Nathan said, using habtm to represent a simple many-to-many > relationship is not deprecated. > -- > Rick DeNatale > > My blog on Ruby > http://talklikeaduck.denhaven2.com/Yes, but I have some additional attributes I want to include in the join. One of this is :position. But let''s not argue over if it''s deprecated or not. Is there a rails way to achieve what I want? -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On 16 Jan 2008, at 08:37, Leon Bogaert wrote:> > Hi all, > > I have a question about how utilizing has_many. > I wrote the code without an editor & testing, so it could contain some > errors. > > Oh, and also don''t mind the weird parent/child relationships here :) > http://pastie.caboo.se/139456 > > I want to be able to do something like: > Parent.find(:first).children[0].active > > How can I achieve this? With has_and_belongs_to_many this was easy. > But > I was fiddling with has_many and I could not get it working like this. >That looks plausible. what problems are you having (do you have a ChildrenParent model ? You''ll need one) Fred> What am I doing wrong? > > Thanks in advance! > -- > 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On 1/16/08, Frederick Cheung <frederick.cheung-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> > > On 16 Jan 2008, at 08:37, Leon Bogaert wrote: > > > > > Hi all, > > > > I have a question about how utilizing has_many. > > I wrote the code without an editor & testing, so it could contain some > > errors. > > > > Oh, and also don''t mind the weird parent/child relationships here :) > > http://pastie.caboo.se/139456 > > > > I want to be able to do something like: > > Parent.find(:first).children[0].active > > > > How can I achieve this? With has_and_belongs_to_many this was easy. > > But > > I was fiddling with has_many and I could not get it working like this. > > > That looks plausible. what problems are you having (do you have a > ChildrenParent model ? You''ll need one)Right, he does and it need to belong_to both parent and child. I also seems to me that it could use a better name, although I can''t think of what that should be without a bit more knowledge of his domain. -- Rick DeNatale My blog on Ruby http://talklikeaduck.denhaven2.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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
class ChildrenParent belongs_to :parent belongs_to :child end class Parent < ActiveRecord::Base has_many :children_parents has_many :children, :through => :children_parents end class Child < ActiveRecord::Base has_many :children_parents has_many :parents, :through => :children_parents end That should do it. :) --Jeremy On Jan 16, 2008 3:37 AM, Leon Bogaert <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > Hi all, > > I have a question about how utilizing has_many. > I wrote the code without an editor & testing, so it could contain some > errors. > > Oh, and also don''t mind the weird parent/child relationships here :) > http://pastie.caboo.se/139456 > > I want to be able to do something like: > Parent.find(:first).children[0].active > > How can I achieve this? With has_and_belongs_to_many this was easy. But > I was fiddling with has_many and I could not get it working like this. > > What am I doing wrong? > > Thanks in advance! > -- > Posted via http://www.ruby-forum.com/. > > > >-- http://www.jeremymcanally.com/ My books: Ruby in Practice http://www.manning.com/mcanally/ My free Ruby e-book http://www.humblelittlerubybook.com/ My blogs: http://www.mrneighborly.com/ http://www.rubyinpractice.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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On Jan 16, 8:42 am, "Jeremy McAnally" <jeremymcana...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> class ChildrenParent > belongs_to :parent > belongs_to :child > endHow about Birth? And if the :position attribute were birth order, it could be replaced by birthdate. ///ark --~--~---------~--~----~------------~-------~--~----~ 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe@googlegroups.com For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Tried the code above and got something like:>> p = Parent.find(:first) >> p.children.length=> 2>> p.children_parents.length=> 2>> p.children_parents[0].position=> 0>> p.children[0].position=> NoMethodError: undefined method `position'' for #<Child:0xb76b4114> from /usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/attribute_methods.rb:205:in `method_missing'' from (irb):3 And p.children[0].position is what I would like to use. When I use has_and_belongs_to_many this works. -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
I thought about using something like:
alias_method(:method_missing_old, :method_missing)
def method_missing(methodname, *args)
return song.send(methodname) if args.empty?
child.send(methodname, args)
end
in the ChildrenParent class. But I don''t know how fragile/stable this
is.
--
Posted via http://www.ruby-forum.com/.
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On 1/16/08, Leon Bogaert <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > Tried the code above and got something like:Which code above in particular?> >> p = Parent.find(:first) > >> p.children.length > => 2 > >> p.children_parents.length > => 2 > >> p.children_parents[0].position > => 0 > >> p.children[0].position > => NoMethodError: undefined method `position'' for #<Child:0xb76b4114> > from > /usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/attribute_methods.rb:205:in > `method_missing'' > from (irb):3 > > And p.children[0].position is what I would like to use. When I use > has_and_belongs_to_many this works. > -- > Posted via http://www.ruby-forum.com/. > > > >-- Rick DeNatale My blog on Ruby http://talklikeaduck.denhaven2.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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
I used the code from Jeremy. -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On 1/16/08, Leon Bogaert <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > I used the code from Jeremy.Okay, so the problem is this>> p.children_parents[0].position=> 0>> p.children[0].position=> NoMethodError: undefined method `position'' for #<Child:0xb76b4114> Which is right, Child has not position attribute it''s in the ChildrenParent. Now the problem is that a child has_many children_parents, so we can''t just do p.children[0].children_parent.position We need to say WHICH of the many possible childrenParents we''re talking about, Now I''m guessing that the logic actually dictates that there really is only one, in which case we can do p.children[0].children_parent[0].position or p.children.find(:first).children_parent.find(:first).position However the right way to do this, IMHO would be to do this: class Child def position children_parent.find(:first).position end end But of course this raises the question of why position isn''t just a simple attribute of Child, in which case I''d seriously consider dropping back to HABTM. If there really are multiple ChildrenParents associated with a single Child, then you do need to figure out which one you are getting the position of. -- Rick DeNatale My blog on Ruby http://talklikeaduck.denhaven2.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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Thanks Rick. I''ll explain what I''m trying to do. I''m creating a website where people (at our company) can vote at songs. The song with the most votes gets played. So I now have: Playlist, Song, PlaylistItem But I dont''t find:>> p = Playlist.find(:first) >> p.playlist_items[0].position >> p.playlist_items[0].top_top >> p.songs[o].title >> p.songs[o].artistmake sence. Maybe it''s the naming of the objects I''ve done. Does someone know a better name for the join class so it makes more sence doing the position-thing on that model instead of song? -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On 1/17/08, Leon Bogaert <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > Thanks Rick. > > I''ll explain what I''m trying to do. > > I''m creating a website where people (at our company) can vote at songs. > The song with the most votes gets played. > > So I now have: > Playlist, Song, PlaylistItem > > But I dont''t find: > > >> p = Playlist.find(:first) > >> p.playlist_items[0].position > >> p.playlist_items[0].top_top > >> p.songs[o].title > >> p.songs[o].artist > > make sence. > > Maybe it''s the naming of the objects I''ve done. Does someone know a > better name for the join class so it makes more sence doing the > position-thing on that model instead of song?So where are the votes in this model? Why not put a vote count attribute in the Song which voting increments? If you want to actually hold the votes in the database then you can do something like: class Vote < ActiveRecord::Base belongs_to :song belongs_to :voter .. end def Song < ActiveRecord::Base has_many :votes, :counter_cache => true # and add a votes_count column to the table def self.most_popular find(:first, :order => "vote_count DESC") end ... end -- Rick DeNatale My blog on Ruby http://talklikeaduck.denhaven2.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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On Wed, 16 Jan 2008 09:37:18 +0100, Leon Bogaert wrote:> Oh, and also don''t mind the weird parent/child relationships here > http://pastie.caboo.se/139456 > > I want to be able to do something like: > Parent.find(:first).children[0].activeI''m struggling, possibly, with the *exact* same problem. Hmm, except that I''m using has_many :through, while yours is HABTM :( That being said, how is your interface? Do you have an interface to associate a specific "child" with a "parent"? Feel free to contact me by e-mail to trade notes. -Thufir --~--~---------~--~----~------------~-------~--~----~ 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On Wed, 16 Jan 2008 18:55:01 -0500, Rick DeNatale wrote:> If there really are multiple ChildrenParents associated with a single > Child, then you do need to figure out which one you are getting the > position of.What about foster children, or step-parents? -Thufir --~--~---------~--~----~------------~-------~--~----~ 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---