HABTM Self referential - only saves one way to join table

rubyonrails-talk
1

I'm completely stumped by this. Basically, I've got an HABTM self referential model set up and for some reason the join table is only saving relationships one way. To illustrate this:

member1 = Member.new member2 = Member.new member1.friends[0] = member2 member1.save member2.friends[0] = member1 member2.save

Both saves return true in the console, but only the first actually is written to the sqlite join table. I've tested a number of more in depth examples, and in every case, I'm only able to get data saved in one direction in the join table. For example:

member_id | friend_id 1 2 1 3 2 3 2 1 This won't save 3 2 This won't save either

In the console everything shows up correctly if I list .friends for any object. But after restarting the console, only the uni-directional entries remain.

Any help would be greatly appreciated! In my project I need to be able to call .friends on any member and receive all members they are friends with. Here's my code:

        # Member object class CreateMembers < ActiveRecord::Migration   def self.up     create_table :members do |t|       t.string :name       t.timestamps     end   end

  def self.down     drop_table :members   end end

      # Join table class CreateMembersFriends < ActiveRecord::Migration   def self.up     create_table :members_friends, :id => false do |t|       t.integer :member_id       t.integer :friend_id     end   end

  def self.down   end end

      # Model class Member < ActiveRecord::Base   has_and_belongs_to_many :friends,                           :class_name => "Member",                           :join_table => "members_friends",                           :foreign_key => "member_id",                           :association_foreign_key => "friend_id" end

2

Bob,

in HABTM are table names in alphabetical order, so your table name should be friends_members...

tom

Bob Mr. wrote:

3

Tom Z Meinlschmidt wrote:

Bob,

in HABTM are table names in alphabetical order, so your table name should be friends_members...

tom

Bob Mr. wrote:

      t.integer :member_id class Member < ActiveRecord::Base   has_and_belongs_to_many :friends,                           :class_name => "Member",                           :join_table => "members_friends",                           :foreign_key => "member_id",                           :association_foreign_key => "friend_id" end

Thanks Tom, but unfortunately that doesn't solve the problem. I need to be able to get the friends of any member. Currently, the join table is only saving it one way. So, for example with the join below, when I try to get member2.friends, the result is nothing. If I try to get member.friends, however, the result is [2, 3]. What I need is to be able to call member2.friends and get the correct result of [1, 3]. Any other ideas?

1 | 2 1 | 3 3 | 2