Question

我想创建一个新的“AnswerStat”对象并将其保存在数据库中。我得到了：

can't write unknown attribute `answer_stat_id'

app/models/answer_stat.rb:14:in `new'
app/models/answer_stat.rb:14:in `add_answer'
app/controllers/users_controller.rb:31:in `block in index'
app/controllers/users_controller.rb:30:in `each'

answer_stat_id不存在，它指的是表answer_stats的主键是id。我当然没有明确声明这个属性。为什么Rails会寻找这个不存在的属性？代码：

class AnswerStat < ActiveRecord::Base

  attr_accessible :contact, :statement, :answer_sum, :answer_count, :variation

  belongs_to :contact, :class_name => "Friend"
  has_one :statement

  validates_uniqueness_of :contact, :scope => :statement

  def self.add_answer(answer)
    if stat = AnswerStat.find_by_contact_id_and_statement_id(answer.contact.id, answer.statement.id)
    ...........do some stuff...........
    else
      @answer_stat = AnswerStat.new(:contact => answer.contact, :statement => answer.statement, :answer_count => 1, :answer_sum => answer.description, :variation => answer.description)
      @answer_stat.save
    end      
  end

我使用以下命令从rails控制台或任何控制器调用它：

   Answer.all.each do |a|
      AnswerStat.add_answer(a)
   end

answer_stats表（使用PRAGME table_info（answer_stats）的sqlite3）：

0|id|INTEGER|1||1
1|contact_id|integer|0||0
2|answer_sum|integer|0||0
3|answer_count|integer|0||0
4|created_at|datetime|1||0
5|updated_at|datetime|1||0
6|statement_id|integer|0||0
7|variation|integer|0||0

提前致谢

Answer 1

它可能来自statement属性，它引用了一个关联的模型。我认为语句表中有it's looking for an answer_stat_id foreign key。

你应该：

create the associated answer通过@answer_stat.build_statement(...)
如果声明要预先存在stat

在Rails中ActiveRecord :: MissingAttributeError（不能写未知属性）

1 个答案: