Querying Parent Models Based on Related Model Conditions

<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public function posts()
    {
        return $this->hasMany(Post::class);
    }
}

class Post extends Model
{
    public function user()
    {
        return $this->belongsTo(User::class);
    }
}

// --- Usage Examples ---

// Get users who have at least one post with "Laravel" in its title
$usersWithLaravelPosts = User::whereHas('posts', function ($query) {
    $query->where('title', 'like', '%Laravel%');
})->get();

// Get users who have posts published after a certain date
$usersWithRecentPosts = User::whereHas('posts', function ($query) {
    $query->where('created_at', '>', now()->subDays(7));
})->get();

// Get users who have a post with 'Laravel' AND a post with 'Eloquent'
// This implies two separate posts (or one post matching both)
$usersWithBothKeywords = User::whereHas('posts', function ($query) {
    $query->where('title', 'like', '%Laravel%');
})->whereHas('posts', function ($query) {
    $query->where('title', 'like', '%Eloquent%');
})->get();


// Get users who DO NOT have any posts
$usersWithoutPosts = User::doesntHave('posts')->get();

// Get users who have posts with 'Laravel' OR who have no posts at all
$usersWithLaravelOrNoPosts = User::whereHas('posts', function ($query) {
    $query->where('title', 'like', '%Laravel%');
})->orDoesntHave('posts')->get();