数据库调用问题

Question

我一直在努力想出一个数据库调用，从问卷表中的“选择”栏给我所有的信息。我能够迭代并列出自己的选择，但是它们有自己的索引值。

代码@choices = Questionnaire.select(:choices).all[0]只给了我第一个

我希望数据库调用是@choices = Questionnaire.select(:choices).all[i]，允许我访问所有这些调用。我试过我能想到的循环。如果外面有人有空，请帮帮我。我在这件事上挣扎了一整天。谢谢!

问卷主计长

class QuestionnairesController < ApplicationController

  def index

    @questions = Questionnaire.find(params[:category_id])
    #params[:category_id]= <%=category.id%>
    @category = Category.find(params[:category_id])
    @videos = VideoClue.find(params[:category_id])

    render :show
    ###render :show Renders Html page
  end

  def choose_answer

    @questions = Questionnaire.find(params[:id])
    @choices = Questionnaire.select(:choices).all

    render :choose_answer
  end
end

结束

Choose_answer.html

<h1>Congrats You Hit The Choices Page!</h1>


<%= semantic_form_for @questions.choices do |c| %>
  <%= c.inputs do |e| %>
    <%= c.input :answer, :as => :check_boxes , :collection => @choices%>
  <% end %>
<% end %>

种子

Questionnaire.create({question: "In that year did MTV (Music     Television) premiere and what was the first music video the channel    aired?", 
  choices:'1982 Michael Jackson Bille Jean, 1984 Madonna Like a virgin, 1981 The Buggles Video Killed The Radio Star', correct_answer:"1981 The Buggles 'Video Killed The Radio Star' ", category_id:1})

Questionnaire.create({question: "This sitcom featured four girls living under one roof. They attended the same boarding school, ran a shop together and reside in a town called Peekskill." , choices:'Designing Women, The Facts of Life, Girlfriends', correct_answer:'The Facts of Life', category_id: 2})

Questionnaire.create({question: "This martial arts film premiere in 1985 which featured a young man who studies Bruce Lee's techniques while on the search for his master. This was set in New York City." , choices:'The Last Dragon, The Karate Kid, Big Trouble in Little China', correct_answer:'The Last Dragon', category_id: 3})

Questionnaire.create({question:"This game launched in 1991 on Sega Genesis which the player's mission is to collect as many golden rings as possible", choices:'Battletoads, Sonic The Hedgehog, Jewel Master', correct_answer: "Sonic The Hedgehog", category_id:4})

Questionnaire.select(“选择”).all返回

     [<Questionnaire:0x007fbc2c9fa728
      id: nil,
      choices: "1982 Michael Jackson Bille Jean, 1984 Madonna Like a           virgin, 1981 The Buggles Video Killed The Radio Star">,
    <Questionnaire:0x007fbc2c9fa138 id: nil, choices: "Designing   Women, The Facts of Life, Girlfriends">,
    <Questionnaire:0x007fbc2ca01dc0 id: nil, choices: "The Last  Dragon, The Karate Kid, Big Trouble in Little China">,
    <Questionnaire:0x007fbc2ca00f88 id: nil, choices: "Battletoads, Sonic The Hedgehog, Jewel Master">]

Answer 1

choices: '1982 Michael Jackson Bille Jean, 1984 Madonna Like a virgin,
1981 The Buggles Video Killed The Radio Star'

首先要考虑的是，为什么要将所有可能的选择存储为单个字符串？你怎么知道第一个选项的文本在哪里结束，第二个选项从哪里开始？

因此，您的第一步应该是将包含字符串的单个选项划分为，ehm，选项数组。这可以通过

• 数据库重组(从string到array类型的转换)；
• 拆分初始字符串(但如果您的某些选择包含逗号，则情况会很糟) Questionnaire.first.choices.split('，‘') # => "1982 Michael“，”1984年麦当娜像处女一样“，”1981年Buggles视频杀死了电台明星“

这样做之后，您应该能够在视图(或rails控制台)中迭代choices。此步骤根据您先前选择的选项而有所不同。