关于Python的pymssql模块,之前研究时总结了“pymssql默认关闭自动模式开启事务行为浅析”这篇博客，但是在测试过程中又发现了几个问题，下面对这些问题做一些浅析，如有不足或不正确的地方，敬请指出。
1： pymssql的commit函数可以提交两次或多次
Connection.commit()：
Commit current transaction. You must call this method to persist your data if you leave autocommit at its default value, which is False
我们知道pymssql模块里面有commit函数表示提交事务，由于某个特殊原因，测试过程中发现执行多次commit都OK，不会报错，如下代码所示。
# -*- coding: utf-8 -*-
'''
-------------------------------------------------------------------------------------------
-- Script Name : TranTest.py
-------------------------------------------------------------------------------------------
'''
import pymssql
import logging
import os.path
import os
import base64
from cryptography.fernet import Fernet
key=bytes(os.environ.get('key'),encoding="utf8")
cipher_suite = Fernet(key)
with open('/home/konglb/python/conf/ms_db_conf.bin', 'rb') as file_object:
for line in file_object:
encryptedpwd = line
decrypt_pwd = (cipher_suite.decrypt(encryptedpwd))
password_decrypted = bytes(decrypt_pwd).decode("utf-8") #convert to string
env_db_user=os.environ.get('db_user')
db_user=base64.b64decode(bytes(env_db_user, encoding="utf8"))
dest_db_conn = pymssql.connect(host=os.environ.get('db_host'),
user=bytes.decode(db_user),
password=password_decrypted,
database='master',
charset="utf8");
sub_cursor = dest_db_conn.cursor(as_dict=True)
sub_cursor.execute('SELECT COUNT(*) AS RecordNum FROM msdb.dbo.sysmail_account')
result_rows =sub_cursor.fetchone()
print(result_rows["RecordNum"])
dest_db_conn.commit()
dest_db_conn.commit()
dest_db_conn.close()