尝试使用 Python 和 Sqlite3 时出现 NoneType 错误

Question

cursor.execute(f"SELECT user_id, Class, Health, Mana, Defense, Maxmana, Maxhealth, Attack, Critical FROM savefile WHERE user_id = '{message.author.id}'")
           result1 = cursor.fetchone()
           classs = int(result1[1]); health = int(result1[2]); mana = int(result1[3]); defense = int(result1[4]); attack = int(result1[7]); critical = int(result1[8])
           sql = "UPDATE savefile SET Class = ? AND SET Health = ? AND SET Mana = ? AND SET Defense = ? AND SET Maxmana = ? AND SET Maxhealth = ? AND SET Attack = ? AND SET Critical = ? WHERE user_id = ?"
           val = (classs + classplus, str(message.author.id),
                  health + healthplus, str(message.author.id),
                  mana + manaplus, str(message.author.id),
                  defense + defenseplus, str(message.author.id),
                  attack + attackplus, str(message.author.id),
                  critical + criticalplus, str(message.author.id))
           cursor.execute(sql, val)
           db.commit()

这是我正在使用的代码块。我目前正在制作一个不和谐的机器人，并且有几个其他命令可以添加到一列中。但是，在“classs = ...”行，即上面显示的代码中的第三行，（额外的 S 是故意的）我收到此错误：

TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType'

我一般对使用 sqlite 比较陌生，不明白为什么会发生这种情况。我的其他机器人命令中有类似的代码，但不明白为什么这特别不起作用。提前感谢您的帮助！

Answer 1

这些结果之一（result1[i]）很可能是 NoneType，这意味着没有从数据库中检索到数据：

classs = int(result1[1]); health = int(result1[2]); mana = int(result1[3]); defense = int(result1[4]); attack = int(result1[7]); critical = int(result1[8])