一 简介 Python和MySQL交互的模块有 MySQLdb 和 PyMySQL(pymysql),MySQLdb是基于C 语言编写的,而且Python3 不在支持MySQLdb 。PyMySQL是一个纯Python写的MySQL客户端,它的目标是替代MySQLdb,可以在CPython、PyPy、IronPython和Jython环境下运行,PyMySQL在MIT许可下发布。
在开发基于Python语言的项目中,为了以后系统能兼容Python3,我们使用了PyMySQL替换了MySQLdb。下面我们来熟悉一下pymysql的使用。
二 安装方式 pymsql的源码 https://github.com/PyMySQL/PyMySQL ,目前还在持续更新。
- 安装要求:
- Python -- one of the following:
- CPython >= 2.6 or >= 3.3
- PyPy >= 4.0
- IronPython 2.7
- MySQL Server -- one of the following:
- MySQL >= 4.1 (tested with only 5.5~)
- MariaDB >= 5.1
- 安装
- pip install PyMySQL
相关文档 , 强烈建议大家仔细阅读一遍。其用法和MySQLdb相差无几,核心用法一致。这样使用pymysql替换mysqldb的成本极小。
三 基于pymysql的数据库交互 - #!/usr/bin/env python
- # encoding: utf-8
- """
- author: yangyi@youzan
- time: 2015/6/8 上午11:34
- func: 基于pymysql的数据库交互类,支持事务提交和回滚,返回结果记录行数,和insert的最新id
- """
- import pymysql
- from warnings import filterwarnings
- filterwarnings('ignore', category=pymysql.Warning)
- CONNECT_TIMEOUT = 100
- IP = 'localhost'
- PORT = 3306
- USER = 'root'
- PASSSWORD = ''
-
- class QueryException(Exception):
- """
- """
-
-
- class ConnectionException(Exception):
- """
- """
-
- class MySQL_Utils():
- def __init__(
- self, ip=IP, port=PORT, user=USER, password=PASSSWORD,
- connect_timeout=CONNECT_TIMEOUT, remote=False, socket='', dbname='test'):
- self.__conn = None
- self.__cursor = None
- self.lastrowid = None
- self.connect_timeout = connect_timeout
- self.ip = ip
- self.port = port
- self.user = user
- self.password = password
- self.mysocket = socket
- self.remote = remote
- self.db = dbname
- self.rows_affected = 0
-
-
- def __init_conn(self):
- try:
- conn = pymysql.connect(
- host=self.ip,
- port=int(self.port),
- user=self.user,
- db=self.db,
- connect_timeout=self.connect_timeout,
- charset='utf8', unix_socket=self.mysocket)
- except pymysql.Error as e:
- raise ConnectionException(e)
- self.__conn = conn
-
-
- def __init_cursor(self):
- if self.__conn:
- self.__cursor = self.__conn.cursor(pymysql.cursors.DictCursor)
-
-
- def close(self):
- if self.__conn:
- self.__conn.close()
- self.__conn = None
-
- #专门处理select 语句
- def exec_sql(self, sql, args=None):
- try:
- if self.__conn is None:
- self.__init_conn()
- self.__init_cursor()
- self.__conn.autocommit = True
- self.__cursor.execute(sql, args)
- self.rows_affected = self.__cursor.rowcount
- results = self.__cursor.fetchall()
- return results
- except pymysql.Error as e:
- raise pymysql.Error(e)
- finally:
- if self.__conn:
- self.close()
-
- # 专门处理dml语句 delete,updete,insert
- def exec_txsql(self, sql, args=None):
- try:
- if self.__conn is None:
- self.__init_conn()
- self.__init_cursor()
- if self.__cursor is None:
- self.__init_cursor()
-
-
- self.rows_affected=self.__cursor.execute(sql, args)
- self.lastrowid = self.__cursor.lastrowid
- return self.rows_affected
- except pymysql.Error as e:
- raise pymysql.Error(e)
- finally:
- if self.__cursor:
- self.__cursor.close()
- self.__cursor = None
-
- # 提交
- def commit(self):
- try:
- if self.__conn:
- self.__conn.commit()
- except pymysql.Error as e:
- raise pymysql.Error(e)
- finally:
- if self.__conn:
- self.close()
-
- #回滚操作
- def rollback(self):
- try:
- if self.__conn:
- self.__conn.rollback()
- except pymysql.Error as e:
- raise pymysql.Error(e)
- finally:
- if self.__conn:
- self.close()
- # 适用于需要获取插入记录的主键自增id
- def get_lastrowid(self):
- return self.lastrowid
#获取dml操作影响的行数
def get_affectrows(self):
return self.rows_affected
#MySQL_Utils初始化的实例销毁之后,自动提交
def __del__(self):
self.commit()
四 小结 前几天刚刚将我们的系统中的MySQLdb 替换为PyMySQL, 还未遇到问题。欢迎大家使用测试上述脚本,有问题欢迎和我讨论。
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