Question

我有一个简单的AR模型：

class Purchaser < ActiveRecord::Base
  attr_accessor :name
  has_many :purchases

  def initialize(opts={})
    @name = opts[:name]
  end
end

在rails runner脚本中，当我尝试创建一个新的购买者时，我收到了一个交易错误。

purchaser = Purchaser.find_or_create_by(
  name: "Foo"
)

这是错误：

activerecord-4.2.0.beta1/lib/active_record/transactions.rb:373:in `clear_transaction_record_state': undefined method `[]' for nil:NilClass (NoMethodError)
from activerecord-4.2.0.beta1/lib/active_record/transactions.rb:304:in `ensure in rollback_active_record_state!'
from activerecord-4.2.0.beta1/lib/active_record/transactions.rb:304:in `rollback_active_record_state!'
from activerecord-4.2.0.beta1/lib/active_record/transactions.rb:283:in `save'
from activerecord-4.2.0.beta1/lib/active_record/persistence.rb:34:in `create'
from activerecord-4.2.0.beta1/lib/active_record/relation.rb:141:in `block in create'
from activerecord-4.2.0.beta1/lib/active_record/relation.rb:300:in `scoping'
from activerecord-4.2.0.beta1/lib/active_record/relation.rb:141:in `create'
from activerecord-4.2.0.beta1/lib/active_record/relation.rb:211:in `find_or_create_by'
from activerecord-4.2.0.beta1/lib/active_record/querying.rb:6:in `find_or_create_by'

我做错了什么？ Ruby 2.1.2，PostgreSQL。

Answer 1

您正在覆盖ActiveRecord中的initialize方法。您也应该调用super来执行ActiveRecord（父）构造函数。您可以在执行代码后执行此操作。类似的东西：

def initialize(opts={})
   @name = opts[:name]
   super
end

希望这有帮助。

Rails 4.2 + PG - 无法初始化ActiveRecord对象

1 个答案: