我试图在“问题”模型中更新嵌套的question_output属性.一个问题has_one question_output.如果数据库中没有现有的question_outputs,一切都正常.但是如果该记录已经有一个question_output,那么在尝试更新时,我会得到以下内容：
Failed to remove the existing associated question_output. The record
Failed to save when after its foreign key was set to nil.
我会以为allow_destroy会照顾,但唉 – 没有快乐.诚然,我以前没有使用过.但是如果有任何关于如何解决这个问题的想法,我会感激的.相关代码如下：
表格：
= form_for [@question.project,@question],:as => :question,:url => admin_project_question_path(@question.project,@question) do |f|
= render '/shared/form_errors',:model => @question
= f.fields_for :question_output_attributes do |qo|
.field
= qo.label :question_type
= qo.select :question_type,QuestionOutput::QUESTION_TYPES
.field
= qo.label :client_format
= qo.select :client_format,QuestionOutput::CLIENT_FORMATS
.field
= qo.label :required
= qo.check_Box :required
.field
= qo.label :min_input,'Length'
= qo.text_field :min_length
= qo.text_field :max_length
= f.submit 'Save Question Formatting'
问题模型：
class Question < ActiveRecord::Base has_one :question_output accepts_nested_attributes_for :question_output,:allow_destroy => true end
QuestionOutput模型：
class QuestionOutput < ActiveRecord::Base belongs_to :question end
问题控制器：
class Admin::QuestionsController < ApplicationController
def show
@question = Question.find(params[:id])
@question.question_output ||= @question.build_question_output
end
def update
@question = Question.find(params[:id])
if @question.update_attributes(params[:question])
flash[:notice] = t('models.update.success',:model => "Question")
redirect_to admin_project_question_path(@question.project,@question)
else
flash[:alert] = t('models.update.failure',@question)
end
end
end