從數據庫顯示隨機條目到我的視圖

因此，我已經成功地構建了一個MYSQL數據庫，並將一堆信息刮進它。我遇到的問題是我真的很難理解我想從數據庫中顯示一個隨機條目到我的視圖中。我一直在閱讀MVC和渲染，但我顯然缺少一些東西。我想告訴你我到目前爲止所做的，希望能夠從這裏得到一些指導。我覺得我真的很苦惱，因爲它目前是空白的！從數據庫顯示隨機條目到我的視圖

謝謝！

我的模型：

class Sandwich < ActiveRecord::Base 
    attr_accessible :country, :description, :image, :name 
    def self.random_sandwich 
Sandwich.find(:first, :order => "RAND()") 
    end 
end

我的控制器：

class SandwichesController < ApplicationController 
    # GET /sandwiches 
    # GET /sandwiches.json 
    def index 
    @sandwich = Sandwich.random_sandwich 

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

    # GET /sandwiches/1 
    # GET /sandwiches/1.json 
    def show 
    @sandwich = Sandwich.find(params[:id]) 

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

    # GET /sandwiches/new 
    # GET /sandwiches/new.json 
    def new 
    @sandwich = Sandwich.new 

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

    # GET /sandwiches/1/edit 
    def edit 
    @sandwich = Sandwich.find(params[:id]) 
    end 

    # POST /sandwiches 
    # POST /sandwiches.json 
    def create 
    @sandwich = Sandwich.new(params[:sandwich]) 

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

    # PUT /sandwiches/1 
    # PUT /sandwiches/1.json 
    def update 
    @sandwich = Sandwich.find(params[:id]) 

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

    # DELETE /sandwiches/1 
    # DELETE /sandwiches/1.json 
    def destroy 
    @sandwich = Sandwich.find(params[:id]) 
    @sandwich.destroy 

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

來源

2013-04-27 DynastySS

嘗試用隨機的訂購，然後找到第一個項目。 Smth是這樣的：

Sandwich.order("RAND()").first

來源

2013-04-27 23:09:04 Bob

我認爲它會變慢。因爲它將隨機化所有數據並挑選第一個數據。

還有另一種方法。生成一個介於0和總三明治之間的隨機數字 - 1.使用該數字作爲偏移來獲得隨機三明治。

random_number = rand(Sandwich.count) 
random_sandwich = Sandwich.limit(1).offset(random_number)

來源

2013-04-28 12:13:06 qmaruf

從數據庫顯示隨機條目到我的視圖

回答

相關問題