Illuminate - HasMany - Iteration

Question

I am just doing my first exercises with Illuminate (Laravel) on my currently handmade database and website. I would like to improve by using MVC and found Illuminate interesting to use for the interaction with my database.

I worked the day on this bloody tiny code and can't find the problem and I hope someone out there has a good idea for me. Many thanks!

Basic question: Why can't I iterate over the courses to the given semester? While it is possible to call a specific course.

use Illuminate\Database\Eloquent\Model as Eloquent;

class Semester extends Eloquent {
    protected $table      = "tblSemester";
    protected $primaryKey = "SemesterID";

    public function getCourses() {
        // test if semester is correct
        echo $this->SemesterID, " - ", $this->Semestertext, "<br>"; 

        // This works fine and returns the expected result
        $course = $this->hasMany('Course', 'Semester')->first();
        echo $course->Number, " - ", $course->Title;

        // This doesn't work. It returns nothing. 
        // There seems to be no data in $courses (just metadata)
        $courses = $this->hasMany('Course', 'Semester');
        foreach ($courses as $course) {
            echo $course->Number, " - ", $course->Title;
            echo "<br>";
        }

        return "<h1>" . "Test ends" . "</h1>";
    }
}

Many thanks! Tim

Answer 1

First of all

Since you said you are new to 'Laravel' and Want to follow MVC, I thought I may give you some advices.

1. In laravel Models, don't include database manipulation codes. Instead write them in controllers.
2. In Models, only include functions which belongs to a single models instance (non static functions).
   1. relationships
   2. query scopes
   3. accessors / modifiers

Example Model

class Semester extends Model 
{
    protected $table = 'semesters';

    // relationships
    public function cources()
    {
        return $this->hasMany(Cource::class);
    }
}

Example Controller

class SemesterController extends Controller
{
    public function iterateOverCourcesOfGivenSemester()
    {
        // take first semester as an example.
        $givenSemester = Semester::first();

        // all the cources belongs to a given semester.
        $cources = $givenSemester->cources;

        foreach($cources as $cource) {

            // Warning! don't echo anything in a controller, Instead return them to a view.
            echo $course->Number, " - ", $course->Title;
            echo "<br>";
        }
    }
}

Answer 2

Why is this not working:

public function cources()
{
    return $this->hasMany(Cource::class);
}   

But this does:

public function cources()
{
    return $this->hasMany('Course', 'Semester')->get();
}