Php 是什么导致我的 Laravel 8 应用程序中出现此查询生成器错误

我正在开发一个有用户、角色和权限的Laravel 8应用程序.

我try 获取当前用户的list of permissions.

在app\Models\Permission.php年中，我有:

class Permission extends Model {
  use HasFactory;

  protected $fillable = [
    'name', 'list'
  ];
}

在app\Models\Role.php年中，我有:

class Role extends Model {
  use HasFactory;

  protected $fillable = [
    'name', 'permission_id'
  ];
}

在控制器中，我首先得到用户的role id:

$user_role = User::where('email', $user->getMail())->first()->role_id;

然后是权限列表:

$user_permissions = Permission::select (
  "roles.name as role_name",
  "permissions.list as permissions_list",
)
->leftJoin("permissions", "roles.permission_id", "=", "permissions.id")
->where('roles.id', $user_role)
->get();

上述内容旨在等效于此MySQL查询，其效果如下:

SELECT roles.name as role_name, permissions.list AS permissions_list
FROM roles LEFT
JOIN permissions ON roles.permission_id = permissions.id WHERE roles.id = 1

问题

您可以看到上面的Laravel查询生成器失败，并显示以下消息:

Syntax error or access violation: 1066 Not unique table/alias: 'permissions' (SQL: select `roles`.`name`, `permissions`.`list` from `permissions` left join `permissions` on `roles`.`permission_id` = `permissions`.`id` where `roles`.`id` = 1)

我不明白为什么，因为我已经在phpMyAdmin和it个works中测试了MySQL查询.

Where is my mistake?