如何允许具有强参数的数组

我有一个功能正常的Rails 3应用程序，使用has_many:通过关联，这不是，因为我把它重新制作为Rails 4应用程序，让我保存id从相关的模型在Rails 4版本。

这是三个相关的模型是相同的两个版本。

Categorization.rb

class Categorization < ActiveRecord::Base


belongs_to :question
belongs_to :category
end

Question.rb

has_many :categorizations
has_many :categories, through: :categorizations

Category.rb

has_many :categorizations
has_many :questions, through: :categorizations

在两个应用中，类别id都像这样传递到创建动作中

  "question"=>{"question_content"=>"How do you spell car?", "question_details"=>"blah ", "category_ids"=>["", "2"],

在Rails 3应用程序中，当我创建一个新问题时，它会插入到问题表中，然后插入到分类表中

 SQL (82.1ms)  INSERT INTO "questions" ("accepted_answer_id", "city", "created_at", "details", "province", "province_id", "question", "updated_at", "user_id") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)  [["accepted_answer_id", nil], ["city", "dd"], ["created_at", Tue, 14 May 2013 17:10:25 UTC +00:00], ["details", "greyound?"], ["province", nil], ["province_id", 2], ["question", "Whos' the biggest dog in the world"], ["updated_at", Tue, 14 May 2013 17:10:25 UTC +00:00], ["user_id", 53]]
SQL (0.4ms)  INSERT INTO "categorizations" ("category_id", "created_at", "question_id", "updated_at") VALUES (?, ?, ?, ?)  [["category_id", 2], ["created_at", Tue, 14 May 2013 17:10:25 UTC +00:00], ["question_id", 66], ["updated_at", Tue, 14 May 2013 17:10:25 UTC +00:00]]

在rails 4应用程序中，在它处理questioncontroller# create中的参数后，我在服务器日志中得到这个错误

Unpermitted parameters: category_ids

问题只是被插入到问题表中

 (0.2ms)  BEGIN
SQL (67.6ms)  INSERT INTO "questions" ("city", "created_at", "province_id", "question_content", "question_details", "updated_at", "user_id") VALUES ($1, $2, $3, $4, $5, $6, $7) RETURNING "id"  [["city", "dd"], ["created_at", Tue, 14 May 2013 17:17:53 UTC +00:00], ["province_id", 3], ["question_content", "How's your car?"], ["question_details", "is it runnign"], ["updated_at", Tue, 14 May 2013 17:17:53 UTC +00:00], ["user_id", 12]]
(31.9ms)  COMMIT

虽然我没有在Questions模型中存储category_ids，但我将category_ids设置为questions_controller中的一个允许参数

   def question_params


params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids)
end

有人能解释一下我应该如何保存category_ids吗?注意，在categorories_controller中没有创建动作。任意一个应用程序的Rb。

这三个表在两个应用中是一样的

 create_table "questions", force: true do |t|
t.text     "question_details"
t.string   "question_content"
t.integer  "user_id"
t.integer  "accepted_answer_id"
t.datetime "created_at"
t.datetime "updated_at"
t.integer  "province_id"
t.string   "city"
end


create_table "categories", force: true do |t|
t.string   "name"
t.datetime "created_at"
t.datetime "updated_at"
end


create_table "categorizations", force: true do |t|
t.integer  "category_id"
t.integer  "question_id"
t.datetime "created_at"
t.datetime "updated_at"
end

更新

这是Rails 3应用程序的创建操作

  def create
@question = Question.new(params[:question])
respond_to do |format|
if @question.save
format.html { redirect_to @question, notice: 'Question was successfully created.' }
format.json { render json: @question, status: :created, location: @question }
else
format.html { render action: "new" }
format.json { render json: @question.errors, status: :unprocessable_entity }
end
end
end

这是Rails 4应用程序的创建操作

   def create
@question = Question.new(question_params)


respond_to do |format|
if @question.save
format.html { redirect_to @question, notice: 'Question was successfully created.' }
format.json { render json: @question, status: :created, location: @question }
else
format.html { render action: "new" }
format.json { render json: @question.errors, status: :unprocessable_entity }
end
end
end

这是question_params方法

 private
def question_params
params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids)
end