ruby_on_rails rails 4参数丢失或值为空

Question

在日志中获取以下错误消息

ActionController::ParameterMissing - param is missing or the value is empty: user_evaluation_result:

在演练控制器中，在某些条件下，我试图在user_evaluation_results中插入一行。操练控制器的代码行如下。我有种感觉我错过了一些显而易见的东西

   ....
   user_evaluation_result_req = Rails.cache.read("user_evaluation_result_req")
      if user_evaluation_result_req
        id = Rails.cache.read("evaluation_assumption_id")
        @user_evaluation_results = UserEvaluationResult.get_user_evaluation_results(id)
        @result_list.each do |result|          
          if @user_evaluation_results.present?
            puts "user evaluation result present "
          else
            @user_evaluation_result = UserEvaluationResult.new
            @user_evaluation_result.evaluation_assumption_id = id
            @user_evaluation_result.company_listing_id = 124
            @user_evaluation_result.target_share_price_dollars = 7333
            @user_evaluation_result = userEvaluationResult.new(user_evaluation_result_params)
          end
        end   
   ....
   # further down in Drills Controller
    def user_evaluation_result_params
      params.require(:user_evaluation_result).
        permit(:evaluation_assumption_id,
               :company_listing_id,
               :target_share_price_dollars )
   end

user_evaluation_results的值目前是硬编码的，但当我让它正常工作时，这个值就会改变。

user_evaluation_result模型

class UserEvaluationResult < ActiveRecord::Base
  include ActiveModel::ForbiddenAttributesProtection
  before_validation :clean_data

  belongs_to :company_listing
  belongs_to :evaluation_assumption

  validates :evaluation_assumption_id, :company_listing_id, 
      :target_share_price_dollars, presence: true
  validates :target_share_price_dollars, :numericality => { :only_integer => true, 
      :greater_than_or_equal_to => 0}
  validates :company_listing_id, uniqueness: {scope: [:evaluation_assumption_id]}

  def self.get_user_evaluation_results(id)
    where("evaluation_assumption_id = ?", id)
  end

  def target_share_price_dollars
    target_share_price.to_d/1000 if target_share_price
  end
  def target_share_price_dollars=(dollars)
    self.target_share_price = dollars.to_d*1000 if dollars.present?
  end

  private

  def clean_data
    # trim whitespace from beginning and end of string attributes
    attribute_names.each do |name|
      if send(name).respond_to?(:strip)
      send("#{name}=", send(name).strip)
      end
    end
  end
end

user_evaluation_result表

 create_table "user_evaluation_results", force: true do |t|
    t.integer  "company_listing_id"
    t.integer  "target_share_price"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.integer  "evaluation_assumption_id"
  end

欢迎任何帮助，当然也可以张贴更多细节，谢谢皮埃尔。

Answer 1

您的UserEvaluationResult在这里调用：@user_evaluation_result = userEvaluationResult.new(user_evaluation_result_params)是小写的，必须是大写字母，因此Rails知道您指的是User Evaluation Result class。您将得到该错误，因为您定义的params需要一个UserEvaluationResult来对其进行操作，但您并没有提供该错误。