TypeError: 'NoneType' object is not subscriptable Телеграм бот

Не знаю в чем проблема.

Ошибка:

  line 114, in get_subcategory
    self.subcategory_id = self.subcategory[0]
TypeError: 'NoneType' object is not subscriptable

Код:

class SubCatalog():
    def __init__(self) -> None:
        self.sql_path = './data/database.db'

    async def get_subcategory(self, subcategory_id=None):
        async with connect(self.sql_path) as db:

            select = await db.execute('SELECT * FROM subcategory WHERE id = ?', [subcategory_id])
            info = await select.fetchone()
            self.subcategory = info

            self.subcategory_id = self.subcategory[0]
            self.category = self.subcategory[1]
            self.subcategory_name = self.subcategory[2]

            return self.subcategory_id, self.subcategory_name