如何将查询结果赋值给类变量？

import sqlite3

class MyClass:
    result = None  # 创建一个类变量

    def __init__(self):
        self.connection = sqlite3.connect('database.db')
        self.cursor = self.connection.cursor()

    def query_data(self):
        self.cursor.execute("SELECT * FROM table")
        self.result = self.cursor.fetchall()  # 将查询结果赋值给类变量

    def close_connection(self):
        self.cursor.close()
        self.connection.close()

# 使用示例
my_object = MyClass()
my_object.query_data()
print(my_object.result)  # 打印查询结果
my_object.close_connection()