如何计算“回复”实例

Question

我目前正在学习红宝石，并且有一个用户输入的应用程序：

:name
:menu
:rsvp

他们都输入为reply

我希望能够统计当前添加了多少人，并将其显示在索引页面上。 我要如何计算到目前为止到目前为止已向数据库中添加了多少项？

Reply.rb

class Reply < ActiveRecord::Base
  attr_accessible :menu, :name, :rsvp, :user_id
  belongs_to :user
end

User.rb

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me,
                  :first_name, :last_name, :profile_name
  # attr_accessible :title, :body

  has_many :replies

  def full_name
    first_name + " " + last_name
  end
end

回复控制器

class RepliesController < ApplicationController
  # GET /replies
  # GET /replies.json
  def index
    @replies = Reply.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @replies }
    end
  end

  # GET /replies/1
  # GET /replies/1.json
  def show
    @reply = Reply.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @reply }
    end
  end

  # GET /replies/new
  # GET /replies/new.json
  def new
    @reply = Reply.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @reply }
    end
  end

  # GET /replies/1/edit
  def edit
    @reply = Reply.find(params[:id])
  end

  # POST /replies
  # POST /replies.json
  def create
    @reply = Reply.new(params[:reply])

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

  # PUT /replies/1
  # PUT /replies/1.json
  def update
    @reply = Reply.find(params[:id])

    respond_to do |format|
      if @reply.update_attributes(params[:reply])
        format.html { redirect_to @reply, notice: 'Reply was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: "edit" }
        format.json { render json: @reply.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /replies/1
  # DELETE /replies/1.json
  def destroy
    @reply = Reply.find(params[:id])
    @reply.destroy

    respond_to do |format|
      format.html { redirect_to replies_url }
      format.json { head :no_content }
    end
  end
end

我希望这些信息对你有用。

Answer 1

获取用户数：

User.count

在您的控制器中，最好将其放在实例变量中：

@user_count = User.count

要将其显示在典型的ERR视图上：

<%= @user_count %>

所有典型的ActiveRecord模型，控制器和视图都是这样工作的。