小编Pav*_*l S的帖子

最近我遇到了rails 4和HABTM关系的神秘错误.首先我的Gemfile:

source 'https://rubygems.org'
gem 'rails', '~> 4.1.6'
gem 'pg'

下一个.我的模特:

class User < ActiveRecord::Base
end

class Teacher < User
  has_and_belongs_to_many :resources, foreign_key: :user_id
end

class Resource < ActiveRecord::Base
  has_and_belongs_to_many :teachers, association_foreign_key: :user_id
end

原始数据库数据:

select * from resources;
 id |         created_at         |         updated_at
----+----------------------------+----------------------------
  1 | 2014-10-13 08:24:07.308361 | 2014-10-13 08:24:07.308361
  2 | 2014-10-13 08:24:07.889907 | 2014-10-13 08:24:08.156898
  3 | 2014-10-13 08:24:08.68579  | 2014-10-13 08:24:08.884731
  4 | 2014-10-13 08:24:09.997244 | 2014-10-13 08:24:10.205753
(4 rows)

select * from users;
 id …