Python通用的创建数据库连接方法

json文件参数

'''
 def __init__(self, host=None, user=None, password="",
                 database=None, port=0, unix_socket=None,
                 charset='', sql_mode=None,
                 read_default_file=None, conv=None, use_unicode=None,
                 client_flag=0, cursorclass=Cursor, init_command=None,
                 connect_timeout=10, ssl=None, read_default_group=None,
                 compress=None, named_pipe=None,
                 autocommit=False, db=None, passwd=None, local_infile=False,
                 max_allowed_packet=16*1024*1024, defer_connect=False,
                 auth_plugin_map=None, read_timeout=None, write_timeout=None,
                 bind_address=None, binary_prefix=False, program_name=None,
                 server_public_key=None):
'''
#例：
{"host":"127.0.0.1",
  "user":"root",
  "password":"******",
  "database":"newtest",
  "port":3306,
  "charset":"utf8"
}

import pymysql
import json
class BaseDao():
    '''
    通用的创建数据库连接方法
    '''
    def __init__(self,configfile='mysql.json'):
        self.config=json.load(open(configfile))
        self.connection=None
        self.cursor=None
        pass
    def getConnection(self):
        if self.connection!=None:
            return self.connection
        try:
            self.connection=pymysql.connect(** self.config)
            self.connection.autocommit(0)
        except Exception as e:
            print("数据库连接失败，请检查配置参数")
            pass
        print("数据库连接成功")
        return self.connection
        pass
    def execute(self,sql,params=None):
        '''
        封装执行语句的方法
        :param sql: 语句
        :param params: 参数列表
        :return:
        '''
        result=0
        try:
            self.cursor=self.getConnection().cursor()
            if params: #if None!=None   if None:False
                result=self.cursor.execute(sql,params)
            else:
                result=self.cursor.execute(sql)
        except Exception as e:
            print(e)
        return result
    def fetch(self):
        if self.cursor:
            return self.cursor.fetchall()
        pass
    # 处理事务管理
    def commit(self):
        if self.connection:
            self.connection.commit()
        pass
    # 回滚
    def rollback(self):
        if self.connection:
            self.connection.rollback()
        pass
    # 关闭连接
    def close(self):
        if self.connection:
            self.connection.close()
        pass