Python类操作MySQL报错：'MySQLConnection'对象无'execute'属性

问题场景 #

使用Python操作本地MySQL服务器，单独编写读写方法时可正常运行，但将方法封装到DatabaseOperations类后，调用readFromDatabase和writeToDatabase方法出现如下错误：

AttributeError: 'MySQLConnection' object has no attribute 'execute'

类实现代码如下：

# DATABASE STUFF
class DatabaseOperations:
    def __init__(self):
        self.local_ip = '192.168.105.181'  # LOCAL MACHINE SERVER RUNNING ON
        self.s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)  # SOCK_DGRAM refers to UDP
        self.s.connect((self.local_ip, 80))
        self.db_connection = mysql.connector.connect(
            host="localhost",
            user="myuser",
            password="12345",
            database="Testing"
        )

    def readFromDatabase(self):
        db_cursor = self.db_connection
        db_cursor.execute(
            f"select * from receiving;"
        )
        db_result = db_cursor.fetchall()
        print(db_result)

    def writeToDatabase(self):
        db_cursor = self.db_connection

        # Loop through ResultsLists and print value at given index position
        for i in range(len(globalResultsList)):
            print(f'RESULTS FROM LOOP: {globalResultsList[i]}')

            # If the next iterator is larger than the length of the list => break out of loop
            if i+1 >= len(globalResultsList):
                return

        db_cursor.execute(
            f"INSERT INTO receiving (client_ip, client_message) VALUES( '{globalClient}', '{globalResultsList[0]}');"
        )
        self.db_connection.commit()
        db_cursor.close()

错误原因 #

核心问题是把数据库连接对象（MySQLConnection）当成了游标对象（Cursor）使用：

• 单独写方法时，你应该是先通过连接创建游标（cursor = connection.cursor()），再用游标执行SQL；
• 但类实现中，你直接将self.db_connection赋值给db_cursor，而MySQLConnection对象本身没有execute方法——这个方法是游标对象的专属方法。

修复方案 #

修改两个读写方法，先通过数据库连接创建游标，再用游标执行SQL：

修复后的readFromDatabase方法 #

def readFromDatabase(self):
    db_cursor = self.db_connection.cursor()  # 创建游标对象
    db_cursor.execute("select * from receiving;")
    db_result = db_cursor.fetchall()
    print(db_result)
    db_cursor.close()  # 用完关闭游标释放资源

修复后的writeToDatabase方法 #

def writeToDatabase(self):
    db_cursor = self.db_connection.cursor()  # 创建游标对象

    for i in range(len(globalResultsList)):
        print(f'RESULTS FROM LOOP: {globalResultsList[i]}')
        if i+1 >= len(globalResultsList):
            return

    # 改用参数化查询，避免SQL注入风险
    db_cursor.execute(
        "INSERT INTO receiving (client_ip, client_message) VALUES(%s, %s);",
        (globalClient, globalResultsList[0])
    )
    self.db_connection.commit()
    db_cursor.close()

额外注意事项 #

• 禁止用f-string拼接SQL：这会引发严重的SQL注入漏洞，必须使用参数化查询（如上述代码中的%s占位符）；
• 类中初始化的socket连接与数据库操作无关，建议移除，避免不必要的资源占用；
• 可在类的__del__方法中添加数据库连接关闭逻辑，或使用上下文管理器（with语句）管理连接和游标，确保资源正常释放。

内容的提问来源于stack exchange，提问作者user8901723980173