为什么这个错误不是异常答案

【问题标题】：Why isn't this error an exception为什么这个错误不是异常
【发布时间】：2018-08-18 05:50:13
【问题描述】：

我有以下代码：

    query = "SELECT * FROM `actions` WHERE clientId = '{}'".format(id)
    cursor.execute(query)
    r = cursor.fetchone()

    try:
        query = (
                 "INSERT INTO `actions`(`name`,`price`,`clientId`) VALUES"
                 " ('{}',{}'{}')".format(r['name'],r['price']+10, id)
                 )

        cursor.execute(query)
        self.dbconn.commit()

    except:
        print("something wrong")

我收到此错误：

Traceback (most recent call last):
  File "/opt/trybinance01/collector.py", line 179, in function1
    cursor.execute(query)
  File "/opt/trybinance01/venv_binance/lib/python3.6/site-packages/pymysql/cursors.py", line 165, in execute
    result = self._query(query)
  File "/opt/trybinance01/venv_binance/lib/python3.6/site-packages/pymysql/cursors.py", line 321, in _query
    conn.query(q)
  File "/opt/trybinance01/venv_binance/lib/python3.6/site-packages/pymysql/connections.py", line 860, in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "/opt/trybinance01/venv_binance/lib/python3.6/site-packages/pymysql/connections.py", line 1061, in _read_query_result
    result.read()
  File "/opt/trybinance01/venv_binance/lib/python3.6/site-packages/pymysql/connections.py", line 1349, in read
    first_packet = self.connection._read_packet()
  File "/opt/trybinance01/venv_binance/lib/python3.6/site-packages/pymysql/connections.py", line 1008, in _read_packet
    recv_data = self._read_bytes(bytes_to_read)
  File "/opt/trybinance01/venv_binance/lib/python3.6/site-packages/pymysql/connections.py", line 1025, in _read_bytes
    data = self._rfile.read(num_bytes)
AttributeError: 'NoneType' object has no attribute 'read'

为什么这没有被异常捕获并打印“有问题”？

【问题讨论】：

这可能发生在cursor.execute 之外的try 块之外。为您的查询提供不同的名称以进行检查。此外，这很容易被注入：see this page
你确定查询的内容是正确的吗？

标签： mysql python-3.x exception

【解决方案1】：

您的代码中有两个cursor.execute()s，其中只有一个受到try/except 块的保护。

我怀疑如果您将回溯中的行 (179) 与源代码中的第 179 行进行比较，您会发现 cursor.execute() 位于 try/except 块之外。

【讨论】：