in laravel where do you find the model code example

Example 1: laravel eloquent get first

// return first row by id
$user = App\User::where('id',$id)->first();
// or return directly a field
$userId = App\User::where(...)->pluck('id');

Example 2: model observer laravel

namespace App;

use Illuminate\Database\Eloquent\Model;

class Post extends Model
{
    protected $table = 'posts';

    protected $fillable = ['title', 'slug', 'content'];

    protected static function boot()
    {
        parent::boot();
        static::saving(function ($model) {
            $model->slug = str_slug($model->title);
        });
    }
}