python - 改进SQL INSERT查询以避免sql注入(inject)

Question

我正在使用 pymyql/mysql-connector 将消息写入 mysql 数据库。这些消息是在 mqtt 代理的回调(paho.mqtt 回调)上进行处理的。我有 4 个不同的表，并且根据消息类型，我将消息插入数据库。我已经编写了插入查询，如下所示。这种编写方式似乎会导致sql注入(inject)。有什么建议可以改进插入查询语句吗？

# callback attached to paho.mqtt.client    
def on_message(self, client, userdata, msg):

    if  msg.topic.startswith("topic1/"):
        self.bulkpayload += "(" + msg.payload.decode("utf-8") + "," + datetime + "),"
    elif msg.topic.startswith("topic2/"):
        self.insertStatement += "INSERT INTO mydatabase.table1 VALUES (" + msg.payload.decode("utf-8") + "," + datetime + ");"
    elif msg.topic.startswith("topic3/")   
        self.insertStatement += "INSERT INTO mydatabase.table2 VALUES (" +msg.payload.decode("utf-8") + "," + datetime + ");"
    elif msg.topic.startswith("messages"):
        self.insertStatement += "INSERT INTO mydatabase.table3 VALUES ('" + msg.topic + "',"  + msg.payload.decode("utf-8") + "," + datetime + ");"
    else:
    return  # do not store in DB

    cursor.execute(self.insertStatement)
    cursor.commit()

Answer 1

使您的查询使用参数。注入(inject)的机会要少得多:

cursor.execute("INSERT INTO table VALUES (%s, %s, %s)", (var1, var2, var3))

信用(和更多信息)在这里:How to use variables in SQL statement in Python?

此外，Dan Bracuk 是正确的 - 如果您尚未验证参数，请确保在执行 SQL 之前验证您的参数