Filter Records Based on Related Model Existence in Eloquent

<?php

namespace App\Http\Controllers;

use App\Models\User;
use App\Models\Post;
use Illuminate\Http\Request;

class QueryingRelationsController extends Controller
{
    public function filterByRelationships()
    {
        // Get all users who have at least one post
        $usersWithPosts = User::has('posts')->get();
        echo "Users with at least one post: " . $usersWithPosts->pluck('name')->implode(', ') . "
";

        // Get all posts that have comments containing 'great'
        $postsWithGreatComments = Post::whereHas('comments', function ($query) {
            $query->where('content', 'like', '%great%');
        })->get();
        echo "Posts with 'great' in comments: " . $postsWithGreatComments->pluck('title')->implode(', ') . "
";

        // Get all users who do NOT have any posts
        $usersWithoutPosts = User::doesntHave('posts')->get();
        echo "Users without any posts: " . $usersWithoutPosts->pluck('name')->implode(', ') . "
";

        // Get all posts that do NOT have any comments from user ID 1
        $postsWithoutCommentsFromUser1 = Post::whereDoesntHave('comments', function ($query) {
            $query->where('user_id', 1);
        })->get();
        echo "Posts without comments from User 1: " . $postsWithoutCommentsFromUser1->pluck('title')->implode(', ') . "
";

        return "Relationship filtering complete. Check console/logs.";
    }
}

// In your User model (App\Models\User.php):
// public function posts()
// {
//     return $this->hasMany(Post::class);
// }

// In your Post model (App\Models\Post.php):
// public function comments()
// {
//     return $this->hasMany(Comment::class);
// }