学习pymysql的一个简单示例

 学习pymysql的一个简单示例

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
    功能：pymysql简单实例
    环境：python3.7
    日期：2019/9/9 21:15
    作者：指尖魔法师
    版本：1.0
"""
from pymysql import connect

class JD(object):
    def __init__(self):
        self.conn = connect(host='localhost', port=3306, user='root',
                            password='123456', database='jingdong', charset='utf8')
        self.cr = self.conn.cursor()

    def __del__(self):
        self.cr.close()
        self.conn.close()

    def execute_sql(self, sql):
        """执行查询语句"""
        self.cr.execute(sql)
        result = self.cr.fetchall()
        for temp in result:
            print(temp)

    def show_all_items(self):
        """显示所有商品"""
        sql = 'select * from items;'
        self.execute_sql(sql)

    def show_cates(self):
        """显示所有分类"""
        sql = 'select * from cates;'
        self.execute_sql(sql)

    def show_brands(self):
        """显示所有品牌"""
        sql = 'select * from brands;'
        self.execute_sql(sql)

    def add_item(self):
        """新增商品"""
        itemname = input("请输入商品名称：")
        cateid = int(input("请输入类别编号："))
        brandid = int(input("请输入品牌编号："))
        parms = [itemname, cateid, brandid]
        sql = 'insert into items values(0,%s,%s,%s);'
        self.cr.execute(sql, parms)
        self.conn.commit()

    def del_item(self):
        """删除商品"""
        itemid = int(input("请输入需要删除的商品编号："))
        sql = 'delete from items where id = %s;'
        parms = [itemid]
        self.cr.execute(sql, parms)
        self.conn.commit()

    def login(self):
        """登录判断"""
        ret = False
        while True:
            user = input("请输入账号或'q'退出：")
            if user == 'q':
                return False
            psw = input("请输入密码：")
            parms = [user]+[psw]
            sql = 'select * from admin where username=%s and password=%s;'
            self.cr.execute(sql, parms)
            ret = self.cr.fetchone()
            if ret:
                return True
            else:
                print("账号或者密码输入错误，请重新输入！")

    def print_sel(self):
        """打印选择列表"""
        print("---------京东商城产品管理系统--------")
        print("1.显示所有商品")
        print("2.显示所有分类")
        print("3.显示所有品牌")
        print("4.新增商品")
        print("5.删除商品")
        print("6.退出")
        return input("请选择：")

    def run(self):
        if self.login():
            while True:
                num = self.print_sel()
                if num == '1':
                    self.show_all_items()
                elif num == '2':
                    self.show_cates()
                elif num == '3':
                    self.show_brands()
                elif num == '4':
                    self.add_item()
                elif num == '5':
                    self.del_item()
                elif num == '6':
                    exit()
                else:
                    print("输入错误，请重新选择！")


def main():
    jd = JD()
    jd.run()


if __name__ == '__main__':
    main()

表结构创建语句

create database jingdong charset=utf8;

use jingdong;

create table admin(
    id int unsigned auto_increment not null primary key,
    username varchar(30) not null,
    password varchar(30) not null
);

insert into admin values(0,'admin','admin'),(0,'888','888');


create table items(
    id int unsigned auto_increment not null primary key,
    itemname varchar(30) not null,
    cate int unsigned not null,
    brand int unsigned not null
);
insert into items values(0,'神州1号',1,3),(0,'神州2号',2,2),(0,'神州3号',1,4),(0,'神州4号',2,3),(0,'神州5号',3,1);

create table cates(
    id int unsigned auto_increment not null primary key,
    catename varchar(30) not null
);
insert into cates values(0,'电脑'),(0,'手机'),(0,'相机'),(0,'电风扇');

create table brands(
    id int unsigned auto_increment not null primary key,
    brandname varchar(30) not null
);
insert into brands values(0,'苹果'),(0,'魅族'),(0,'诺基亚'),(0,'明基');