python连接数据库

# -*- coding: utf-8 -*-
'''
Created on 2015-03-19

Mysql 数据库连接类
'''

import MySQLdb

class DBOperate:

    dbhandle = None

    #建立和数据库系统的连接
    def connect(self):
        self.dbhandle = MySQLdb.connect("localhost","username","password","dbname" )

    #获取操作游标
    def cursor(self):
        try:
            return self.dbhandle.cursor()
        except (AttributeError, MySQLdb.OperationalError):
            self.connect()
            return self.dbhandle.cursor()

    def commit(self):
        return self.dbhandle.commit()

    #关闭连接
    def close(self):
        return self.dbhandle.close()
    
    #执行单行sql语句  
    def execute(self,sql):
        conn = self.dbhandle.cursor()
        conn.execute(sql)
     
    #执行多条数据
    def executemany(self,sql, tmp):
        conn = self.dbhandle.cursor()
        conn.executemany(sql, tmp)
    
    #查询某几行sql
    def querymany(self,sql,size):
        conn = self.dbhandle.cursor()
        conn.execute(sql)
        rows = conn.fetchmany(size)
        return rows
    
    #查询1行sql
    def queryone(self,sql):
        conn = self.dbhandle.cursor()
        conn.execute(sql)
        rows = conn.fetchone()
        return rows
        
    #查询所有行sql
    def queryall(self,sql):
        conn = self.dbhandle.cursor()
        conn.execute(sql)
        rows = conn.fetchall()
        return rows