Laravel Eloquent 按关系计数排序

使用Laravel框架的Eloquent ORM可以轻松地操作数据库，包括按关系进行计数排序。在本文中，我们将探讨如何使用Eloquent来执行这样的操作，并提供一个案例代码来说明其用法。

php artisan make:model User
php artisan make:model Post

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

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

php
public function getPostCountAttribute()
{
    return $this->posts->count();
}

php
$users = User::withCount('posts')->orderBy('posts_count', 'desc')->get();

php
// User.php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
    public function posts()
    {
        return $this->hasMany(Post::class);
    }
    public function getPostCountAttribute()
    {
        return $this->posts->count();
    }
}
// Post.php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class Post extends Model
{
    public function user()
    {
        return $this->belongsTo(User::class);
    }
}
// UserController.php
namespace App\Http\Controllers;
use App\Models\User;
class UserController extends Controller
{
    public function index()
    {
        $users = User::withCount('posts')->orderBy('posts_count', 'desc')->get();
        
        return view('users.index', compact('users'));
    }
}