Question

我正在尝试从3个表中显示数据->

课程名称|测试名称|问题计数

课程名称1 |测试名称1 | 3

我在测试和问题1：N之间有关系

Test.php

public $table = 'Test';

protected $fillable = [
    'name',
];

public function question()
{
    return $this->hasMany('App\Question');
}

Question.php

public $table = 'Question';

public function test()
{
   return $this->belongsTo('App\Test');
}

TestController.php

public function courses(Subject $subject) {
    $subject_with_courses = Subject::with(['course'])->where('id', 

    $subject['id'])->first();

    $courses = Course::with(['test'])->get();
    $questions = $courses->question;

    return view('admin.test.list_course', [
        'courses' => $courses,
        'questions' => $questions,
        'subject' => $subject
    ]);
}

list_course.php

@foreach($courses as $course)
    <tr>
        <td>
            {{ $course->name }}
        </td>
        <td>
            @foreach($course->test as $test)
                {{ $test->name }}
            @endforeach
        </td>
        <td>
            @foreach($course->questions as $test)
                {{ $test->count() }}
            @endforeach
        </td>
    </tr>
@endforeach

我收到错误消息“此集合实例上不存在属性[问题]。”

有人可以帮我吗？谢谢！！

Answer 1

这是给您错误的原因：

TestController.php：

$courses = Course::with(['test'])->get();
$questions = $courses->question; // <---- $courses is a Collection not a Model

您正在尝试访问模型的问题属性，但是$courses是模型的集合。

Answer 2

您正在尝试访问课程模型属性，但是$courses是Course的集合

Answer 3

您可以eager load在控制器中提问：

$courses = Course::with(['test', 'test.question'])->get();

问题属于测试而非课程，因此您不能在课程模型上致电$course->question。

在您看来：

@foreach($courses as $course)
    <tr>
        <td>
            {{ $course->name }}
        </td>

        <td>
            @foreach($course->test as $test)
                {{ $test->name }}
            @endforeach
        </td>

        <td>
            @foreach($course->test as $test)
                {{ $test->question->count() }}
            @endforeach
        </td>
    </tr>
@endforeach

显示3个表中的数据Laravel

3 个答案: