python通过原生sql查询数据库（共享类库）

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""DB共享类库"""
# 使用此类,先实例化一个DataBaseParent_local对象,然后对象调用相应方法
# from django.db import connection

import MySQLdb
db = MySQLdb.connect(host="www.szoworld.cn", user="db_test", passwd="qazedc", db="pram_sg", charset="utf8")

class DataBaseParent_local:
    def __init__(self):
        self.cursor = "Initial Status"
        self.cursor = db.cursor()
        if self.cursor == "Initial Status":
            raise Exception("Can't connect to Database server!")

    # 返回元组套元组数据
    def select(self, sqlstr):
        # result = (('apollo', 'male', '164.jpeg'), ('apollo', 'male', ''))
        cur = db.cursor()
        cur.execute(sqlstr)
        List = cur.fetchall()
        iTotal_length = len(List)
        self.description = cur.description
        cur.close()
        return List, iTotal_length

    # 返回列表套字典数据
    def select_include_name(self, sqlstr):
        # result = [{'name':'apollo','age':28},{'name':'jack','age':27}]
        cur = db.cursor()
        cur.execute(sqlstr)
        index = cur.description
        List = cur.fetchall()
        iTotal_length = len(List)
        result = []
        for res in List:
            row = {}
            for i in range(len(index) - 1):
                row[index[i][0]] = res[i]
            result.append(row)
        cur.close()
        return result, iTotal_length

    # 返回指定页码数据（元组套元组）
    def select_for_grid(self, sqlstr, pageNo=1, select_size=5):
        # List: (('apollo','male','28'),('jack','male','27'))
        # iTotal_length: 查询结果元组的长度
        # select_size：分页每页显示
        # pageNo：页码
        List, iTotal_length = self.select(sqlstr)
        # 确定页码
        if iTotal_length % select_size == 0:
            iTotal_Page = iTotal_length / select_size
        else:
            iTotal_Page = iTotal_length / select_size + 1

        start, end = (pageNo - 1) * select_size, pageNo * select_size
        if end >= iTotal_length: end = iTotal_length
        if iTotal_length == 0 or start > iTotal_length or start < 0:
            return [], iTotal_length, iTotal_Page, pageNo, select_size
        # 假设有10条数据，select_size=5，对应结果如下：
        # List[start:end]：(('apollo','male','28'),('jack','male','27')) 10,2，
        # iTotal_length：10
        # iTotal_Page：2
        # pageNo：1
        # select_size：5
        return List[start:end], iTotal_length, iTotal_Page, pageNo, select_size

    # 执行sql语句
    def executesql(self, sqlstr):
        cur = db.cursor()
        r = cur.execute(sqlstr)
        db.commit()
        cur.close()
        return r

    # 插入数据
    def insert(self, sql, param):
        cur = self.cursor
        n = cur.execute(sql, param)
        db.commit()
        cur.close()
        return n

    def release(self):
        return 0