Rails 3 嵌套表单；新的 UnknownAttributeError

Question

Rails 3.1，Ruby 1.87（不要恨我）。我观看了关于嵌套表单的 Railscast；我只是把它放进去，这样你就可以指出我可能在 Railscasts 中遗漏了什么，如果你知道的话。

注意：我添加了@sample_data_set.build_sample_data_template，但在帖子中得到了“未知属性：sample_data_set_id”[代码也与下面的新代码一起发布）。

在创建/新建时使用嵌套表单；点击提交并获取：

ActiveRecord::UnknownAttributeError（未知属性： 样本数据模板）：
app/controllers/sample_data_sets_controller.rb:50:in new'
app/controllers/sample_data_sets_controller.rb:50:increate'

样本数据集模型：

class SampleDataSet < ActiveRecord::Base
  has_one :sample_data_template, :dependent => :destroy
  accepts_nested_attributes_for :sample_data_template
end

样本数据模板模型：

class SampleDataTemplate < ActiveRecord::Base
  belongs_to :sample_data_set
   #Random info generation
  def self.name_gen(*prepend)
    character_map =  [('a'..'z'),('A'..'Z')].map{|i| i.to_a}.flatten
    name  =  (0..8).map{ character_map[rand(character_map.length)]  }.join

    if prepend[0].nil? || prepend[0] == ""
      return name
    else
      return prepend[0].to_s + "_" + name
    end
  end

  def self.ssn_gen
    #broke this out as its own method in case someone wants some logic later one
    ssn = ""
    3.times do
      ssn = ssn + (100..999).to_a.choice.to_s
    end
    return ssn
  end

  def self.row_gen(row_count)
    @data_rows = Array.new
    i = 0
    until i > row_count do
      @row = SampleDataSet.first
      @row.officialFirstName  = SampleDataTemplate.name_gen
      @row.officialLastName   = SampleDataTemplate.name_gen
      @row.emailAddresses     = @row.officialFirstName + @row.officialLastName + "@aaa.aaa.edu"
      @row.ssn                = SampleDataTemplate.ssn_gen
      @data_rows << @row
      i += 1
    end

    return @data_rows
  end
end

示例数据控制器#New

  def new
    @sample_data_set = SampleDataSet.new
    @sample_data_set.build_sample_data_template #after adding this I get error:unknown attribute: sample_data_set_id     
    respond_to do |format|
      format.html # new.html.erb
      format.json { render :json => @sample_data_set }
    end

示例数据控制器#Create

  def create
    @sample_data_set = SampleDataSet.new(params[:sample_data_set])

    respond_to do |format|
      if @sample_data_set.save
        format.html { redirect_to @sample_data_set, :notice => 'Sample data set was successfully created.' }
        format.json { render :json => @sample_data_set, :status => :created, :location => @sample_data_set }
      else
        format.html { render :action => "new" }
        format.json { render :json => @sample_data_set.errors, :status => :unprocessable_entity }
      end
    end
  end
  end

更新，添加表单块

  <div class="sample_fields">
    <%= f.fields_for :sample_data_templates do |builder| %>
      <%= render "sample_data", :f => builder%>
    <% end %>
  </div>

更新，架构：

ActiveRecord::Schema.define(:version => 20120103172936) do

  create_table "sample_data_sets", :force => true do |t|
    t.string   "title"
    t.text     "description"
    t.string   "created_for"
    t.string   "created_by"
    t.integer  "number_of_records"
    t.integer  "sample_data_template_id"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "sample_data_templates", :force => true do |t|
    t.integer  "sample_data_set_id"
    t.string   "irn"
    t.string   "ssn"
    t.string   "officialLastName"
    t.string   "officialFirstName"
    t.string   "emailAddresses"
    t.string   "campusNum"
    t.string   "internationalId"
    t.string   "internationalIdCountry"
    t.string   "gender"
    t.string   "officialMiddleInitial"
    t.string   "previousLastName"
    t.string   "previousFirstName"
    t.string   "previousMiddleInitial"
    t.string   "addressLine1"
    t.string   "addressLine2"
    t.string   "addressLine3"
    t.string   "city"
    t.string   "state"
    t.string   "zipCode"
    t.string   "province"
    t.string   "homeAreaCode"
    t.string   "homePhoneNumber"
    t.string   "homePhoneExtenstion"
    t.string   "homePhoneCountryCode"
    t.string   "workAreaCode"
    t.string   "workPhoneNumber"
    t.string   "workExtenstion"
    t.string   "workPhoneCountryCode"
    t.string   "faxAreaCode"
    t.string   "faxPhoneNumber"
    t.string   "faxExtension"
    t.string   "faxCountryCode"
    t.string   "race"
    t.string   "previousDegree"
    t.string   "region"
    t.string   "foreignTranscript"
    t.string   "apolloEmployee"
    t.string   "nursingLicenseExpiration"
    t.string   "nursingInsuranceExpiration"
    t.string   "otherInsuranceExpiration"
    t.string   "program"
    t.string   "version"
    t.string   "groupId"
    t.string   "team"
    t.string   "enrollmentUserId"
    t.string   "admissionsUserId"
    t.string   "oldProgram"
    t.string   "oldVersion"
    t.string   "galaxyStudentOid"
    t.string   "suffixOne"
    t.string   "suffixTwo"
    t.string   "employeId"
    t.string   "promoCode"
    t.string   "revCampusOid"
    t.string   "FerpaNotes"
    t.string   "isWavierHigh"
    t.string   "executingUserId"
    t.string   "totalDeclaredExtCredits"
    t.datetime "insuranceExpireDate"
    t.datetime "acknowledgementDate"
    t.datetime "scheduledReentryDate"
    t.datetime "scheduledStartDate"
    t.datetime "dateOfBirth"
    t.datetime "enrollAgreeSignDate"
    t.boolean  "usCitizen"
    t.boolean  "financialAid"
    t.boolean  "overrideFlag"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

end

Answer 1

sample_data_templates 表是否有 sample_data_set_id 列？也许您没有将其添加到迁移中或没有运行迁移？