Delete all related comments on deleting a post in Laravel

You can delete all the related comments to a post in laravel using the deleted event.

In Laravel, the deleted event trigger can be used to perform additional actions related to a deleted record. For example, if you have a Post model with a relationship to a Comment model, you can use the deleted event trigger to automatically delete all related comments when a post is deleted.

To delete the comments table records related to posts table record using deleted event, you have to create the posts table with id, title, slug ,body, created_at, updated_at columns and comments table with id, post_id, body, created_at and updated_at columns where post_id is the foreign key related to posts table id column. You also have to create the relationship between two tables (posts and comments) using hasMany relationship in the Post model.

app\Models\Post

class Post extends Model
{
	use HasFactory;

	protected $table = "posts";
	protected $fillable = [
		'title', 'slug', 'body', 'created_at', 'updated_at'
	];

	protected static function boot(){
		parent::boot();
		static::deleted (function($post){
			$post->comments()->delete();
		});
	}
	public function comments(){
		return $this->hasMany (Comment::class);
	}
}

routes/web.php

<?php

use Illuminate\Support\Facades\Route;
use App\Models\Post;
/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/

Route::get('/', function () {
    Post::whereId(1)->first()->delete();
    echo "Post with comments deleted";
});

Manually delete the comments table records

routes/web.php

<?php

use Illuminate\Support\Facades\Route;
use App\Models\Post;
use App\Models\Comment;
/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/

Route::get('/', function () {
    $postId = 1;
    Post::whereId($postId)->delete();
    Comment::wherePostId($postId)->delete();
    echo "deleted";
});