Laravel Eloquent获取所有类别、子级用户以及哪些用户属于角色

// Category.php
class Category extends Model
{
    public function users()
    {
        return $this->hasMany(User::class);
    }
}

// User.php
class User extends Model
{
    public function category()
    {
        return $this->belongsTo(Category::class);
    }

    public function roles()
    {
        return $this->belongsToMany(Role::class);
    }
}

// Role.php
class Role extends Model
{
    public function users()
    {
        return $this->belongsToMany(User::class);
    }
}

// 获取所有类别及其子级用户
$categories = Category::with('users')->get();

foreach ($categories as $category) {
    echo "Category: " . $category->name . "\n";
    foreach ($category->users as $user) {
        echo "  User: " . $user->name . "\n";
        foreach ($user->roles as $role) {
            echo "    Role: " . $role->name . "\n";
        }
    }
}