app-api/app/Models/Course/Comment.php

<?php

namespace App\Models\Course;

use App\Models\User;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;
use DateTimeInterface;

class Comment extends Model
{
    use SoftDeletes;
    protected $connection = 'mysql_c';
    protected $table='comment';
    protected $guarded=[];
    protected function serializeDate(DateTimeInterface $date): string
    {
        return $date->format('Y-m-d H:i:s');
    }

    public function user(){
        return $this->hasOne(User::class,'id','user_id');
    }

    public function course(): \Illuminate\Database\Eloquent\Relations\HasOne
    {
        return $this->hasOne(Course::class,'id','course_id');
    }
}