Laravel Eloquent：我如何定义这种关系？

Question

I have the following tables:

lessons
- lessonID
- lessonName
..

sections
- sectionID
- lessonID references lessons.lessonID
..

exercises
- exerciseID
- sectionID references sections.sectionID
..

I have set up the following relations:

Lesson:

public function sections()
{
    return $this->hasMany('Section', 'lessonID');
}

Section:

public function lesson() {
    return $this->belongsTo('Lesson', 'lessonID');
}

public function exercise() {
    return $this->hasOne('Exercise', 'sectionID');
}

Exercise:

public function section() {
    return $this->belongsTo('Section', 'sectionID');
}

Now I want to say that a Lesson has many Exercises through Sections, so I tried adding

public function exercises()
{
    return $this->hasManyThrough('Exercise', 'Section', 'lessonID', 'sectionID');
}

to the Lessons model and I run

Lesson::with('sections', 'exercises')

gives me an empty array for the exercises. How can I accomplish what I want?

Edit: I'm seeding the Exercise table like so:

<?php

class ExerciseTableSeeder extends Seeder {

public function run()
    {
    DB::table('exercises')->delete();

    Exercise::create(array(
        'exerciseID' => 1,
        'sectionID' => 2,
        ...
        ));

    Exercise::create(array(
        'exerciseID' => 2,
        'sectionID' => 4,
        ...
        ));

    }
}

?>

Edit 2: Here's my models: http://laravel.io/bin/2Rdl

And here are the query logs: http://laravel.io/bin/vebK

So in short: The Lesson and its Sections are returned fine, but I get an empty array for the Exercises.

Answer 1

After I reported the issue on their Github, I got an embarrassingly simple answer: the request should be Lesson::with('sections.exercises') instead.