ruby-on-rails - 一对多关系行为

Question

我对一对多关系有一种我没有得到的行为，这绝对让我发疯。

这是模型1：

class Account < ActiveRecord::Base
  belongs_to :organization, :autosave => true
  validates :organization, :presence => true
end

这是模型2：

class Organization < ActiveRecord::Base
  has_many :accounts, :autosave => true
  validates :accounts, :presence => true
end

现在，在 Rails 控制台中：

>> acc = Account.new
>> org = Organization.new
>> org.accounts << acc

>> org.accounts
[#<Account id: nil, organization_id: nil, created_at: nil, updated_at: nil>]

>> acc.organization
nil

或相反：

>> acc = Account.new
>> org = Organization.new
>> acc.organization = org

>> acc.organization
#<Organization id: nil, created_at: nil, updated_at: nil>

>> organization.accounts
[]

这是正常行为吗？我应该手动更新关系的双方吗？！

Answer 1

答案很简单，先保存对象

acc = Account.new
org = Organization.new 
acc.organization = org
acc.save

Answer 2

参考this使用build

org = Organization.new
acc = org.build_account.new
org.save