create proc GetNewPath
	@parentFolderName nvarchar(255),
	@newpath varchar(675) output
as
	declare @path hierarchyid
	select @path = path_locator
	from Files
	where name = @parentFolderName

	SELECT @newpath = @path.ToString()     +
	CONVERT(VARCHAR(20), CONVERT(BIGINT, SUBSTRING(CONVERT(BINARY(16), NEWID()), 1, 6))) + '.' +
	CONVERT(VARCHAR(20), CONVERT(BIGINT, SUBSTRING(CONVERT(BINARY(16), NEWID()), 7, 6))) + '.' +
	CONVERT(VARCHAR(20), CONVERT(BIGINT, SUBSTRING(CONVERT(BINARY(16), NEWID()), 13, 4))) + '/'
go 

declare @new_path varchar(675)


exec GetNewPath 'root', @new_path output
select @new_path

insert into Files (name, path_locator, is_directory)
	select 'Новая папка', @new_path, 1

exec GetNewPath 'root', @new_path output
select @new_path

insert into Files (name, path_locator, is_directory)
	select 'Проекты', @new_path, 1