administraCursos/app/Section.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class Section extends Model
{

    protected $fillable = [
        'course_id',
        'semester_code',
        'code',
        'credits',
        'student_count',
        'syllabus'
    ];

    public $timestamps = false;

    public function semester() {
        return $this->belongsTo(Semester::class);
    }

    public function course() {
        return $this->belongsTo(Course::class);
    }

    public function professors() {
        return $this->belongsToMany(Professor::class);
    }

    public function getExtraCreditsAttribute() {
        return calcExtraCredits($this->credits, $this->student_count);
    }
}