Python基于pymysql的数据库操作类的安装运行过程
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
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
returnself.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()