检索与多个记录关联的多个记录laravel 4.2 [英] retrieving multiple records associated to multiple records laravel 4.2

问题描述

最近我问这个问题有一个答案，但不幸的是没有解决问题，之后我没有更多的答案，我真的需要解决这个问题我有。

recently i asked this question which got one answer but unfortunately didn't solve the problem, after that i got no more answers and i really need to fix this problem i have.

好的，所以我必须为我的学校做一个测验网站，用户应该可以在其中玩测验，这个页面需要显示测验名称，与测验相关的问题以及与问题相关的答案。
我可以显示测验名称没有问题，我可以显示问题，但由于某些原因，只显示与最终问题相关的答案。

Alright so i have to make a quiz website for my school in which a user should be able to play the quiz, this page need to show the quiz name, the questions associated to the quiz and the answers associated to the questions. I can show the quiz name no problem and i can show the questions aswell, but for some reason only the answers associated to the final question are shown.

这是我的代码：

public function playQuiz($id)
{

    // get all the questions associated to the selected quiz
    $questions = Question::where('quiz_id', $id)->get();

    // get all the answers associated to the questions
    foreach($questions as $question)
    {
        $answers = Answer::where('question_id', $question->id)->get();
    }

    $data = [
        'quiz'      => Quiz::find($id),
        'questions' => $questions,
        'answers'   => $answers
    ];

    return View::make("quizzes.playQuiz", $data);
}

$ id变量是我选择的测验的ID，所以我应该能够检索与此ID相关联的所有数据，以及与此ID相关联的数据相关联的所有数据。

The $id variable is the id of the quiz i selected so i should be able to retrieve all data associated to this id, and all data associated to the associated data of this id.

这是我的html（带刀片）：

Here's my html (with blade):

   <h3>{{ $quiz->name }}</h3>

    @foreach($questions as $question)

            <h4>{{ $question->question }}</h4>

            @foreach($answers as $answer)

                @if($answer->question_id == $question->id)

                        <p>{{ $answer->answer }}</p>

                @endif

            @endforeach

    @endforeach

我知道问题在于我从数据库获取答案的方式，但我不知道如何解决这个问题。帮助非常感谢！感谢您阅读！

I know that the problem lies within the way i get my answers from the db but i don't know how to fix it. Help is much appreciated! Thanks for reading!

*编辑，

我的数据库方案如下：

我有

• 一个名为测验的表格，名称和描述。


• 一个名为问题的表，一个问题和一个外键quiz_id


• 一个名为answer的答案和一个外键question_id / li>
  

• a table called quizzes with an id, name and description.
• a table called questions with an id, question and a foreign key "quiz_id"
• a table called answers with an id, answer and a foreign key "question_id"

一个测验可以有多个问题，但问题只能有一个测验，
a问题可以有多个答案，但答案可以只有一个问题。

a quiz can have multiple questions but a question can only have one quiz, a question can have multiple answers but an answer can only have one question.

我希望这是足够的关于我的数据库的信息，谢谢帮助！

i hope that is enough information about my database, thanks for helping out!

推荐答案

你应该使用Eloquent的关系来解决这个问题。请参阅这里： http://laravel.com/docs/4.2/eloquent#relationships

You should use Eloquent's relationships to solve this problem. See more here: http://laravel.com/docs/4.2/eloquent#relationships

我现在看到的方式是你有三个模型，你正在使用：测验，问题和答案 - 对吗？

The way I see it currently is that you have three models that you're working with: Quiz, Question and Answer - right?

从你的问题我收集以下内容：

From your question I gather the following:

• 一个测验将有很多问题 s


• 答案将属于一个问题

• A Quiz will have many Questions
• An Answer will belong to one Question

所以基于这些假设，我会把模型看成如此...

So based on these assumptions I'd flesh out the models as so...

注意：

• 我一直没有使用4.3，所以你可能需要修改一些代码，但是应该是可以的。


• 下面的模型假设你是用雄辩的期望使用外键，如果不是，你可以将它们定义为第二个关系方法的参数（hasMany，belongs sTo）

Quiz.php

<?php

class Quiz extends Eloquent {

    protected $table = 'quiz'; // or whatever your table is

    public function questions()
    {
        return $this->hasMany('Question'); // this should be the model name
    }

}

Question.php

<?php

class Question extends Eloquent {

    protected $table = 'question'; // or whatever your table is

    public function quiz()
    {
        return $this->belongsTo('Quiz'); // defining the inverse of the relation
    }

    public function answers()
    {
        return $this->hasMany('Answer');
    }

}

Answer.php

<?php

class Answer extends Eloquent {

    protected $table = 'answer'; // or whatever your table is

    public function question()
    {
        return $this->belongsTo('Question');
    }

}

然后您的控制器变为很多清洁

Then your controller becomes a lot cleaner

控制器

public function playQuiz($id)
{
    $quiz = Quiz::find($id);

    return View::make('quizzes', compact('quiz'));
}

查看

<h3>{{ $quiz->name }}</h3>

@foreach($quiz->questions as $question)

        <h4>{{ $question->question }}</h4>

        @foreach($question->answers as $answer)

            <p>{{ $answer->answer }}</p>

        @endforeach

@endforeach

请让我知道如果您在执行上述任何问题上都遇到困难，我会尽力帮助您。首先，关系可能有点棘手，但是一旦你得到你的头，你永远不会回头。

Please let me know if you have any trouble implementing the above and I'll do my best to help out. Relationships can be a bit tricky at first but once you get your head round them you'll never look back.

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