python 操作mysql数据库之模拟购物系统登录及购物

python 操作mysql数据库之模拟购物系统登录及购物，功能包含普通用户、管理员登录，查看商品、购买商品、添加商品，用户充值等。

mysql 数据库shop 表结构创建如下：

create TABLE userinfo (
u_id int(10) not null auto_increment,
u_name varchar(35),
u_passwd varchar(35),
money decimal(10,2),
role int(5),
primary key(u_id)
)CHARACTER set  utf8 COLLATE utf8_general_ci;

CREATE TABLE product(
p_id int(10) NOT NULL auto_increment,
p_name VARCHAR(35),
p_price DECIMAL(10,2),
PRIMARY KEY (p_id)
)CHARACTER SET utf8  COLLATE utf8_general_ci;

create table carts(
c_id int(10) not null auto_increment,
u_id int(10) NOT null,
p_id int(10) NOT null,
PRIMARY key (c_id)
)CHARACTER SET utf8 COLLATE utf8_general_ci;

初始化插入的数据如下：

insert into userinfo (u_name,u_passwd,money,role)VALUES('sp1','',100000.55,1);
insert into userinfo (u_name,u_passwd,money,role)VALUES('sp3','',100000.55,1);
insert into userinfo (u_name,u_passwd,money,role)VALUES('sp3','',100000.55,1);

insert into product(p_name,p_price) values('MI',1999.00);
insert into product(p_name,p_price) values('MAC',1999.00);
insert into product(p_name,p_price) values('iphoneX',1999.00);
insert into product(p_name,p_price) values('VIVO',1999.00);

项目结构如下：

confsetting.py 为配置文件，存放系统常量：

HOST = '172.16.2.163'
USER = 'root'
PASSWD = ''
DB_NAME = 'shop'

lib目录下存放系统功能和常用函数：

mysql.py内容：

def op_mysql(host,user,passwd,db,sql,charset='utf8',port=3306):
    "操作数据库"
    import pymysql
    from pymysql.cursors import DictCursor
    coon = pymysql.connect(host=host,user=user,passwd=passwd,db=db,charset=charset,port=port)
    cur = coon.cursor(DictCursor)  # 定义一个游标，返回一个字典类型
    cur.execute(sql)
    if sql.strip().startswith('select'):
        res = cur.fetchall()
    else:
        coon.commit()
        res = 'ok'
    cur.close()
    coon.close()
    return res

action.py内容：

from conf.confsetting import HOST,USER,PASSWD,DB_NAME
from lib.mysql import op_mysql

def login(u_name, u_pass):
    "用户登录"
    name = str(u_name)
    passwd = str(u_pass)
    res = None
    if not name or not passwd:
        print("error，用户名或密码不能为空！")
    else:
        my_sql = "select u.u_id,u.u_name,u.u_passwd,u.money,u.role from userinfo u where u.u_name='%s';" % name
        user_info = op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql)
        if len(user_info) == 0:
            print('error,用户名不存在')
        else:
            for u in user_info:  # 可能存在同名
                if u['u_passwd'] == passwd:
                    print('用户：{u} 登录成功!'.format(u=u))
                    res = u
            if not res:
                print('error,密码输入错误')
    return res

def get_goods():
    "查询所有商品"
    my_sql = "select p.* from product p;"
    goods_info = op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql)
    print('success，查询所有商品成功,商品信息：', goods_info)
    return goods_info

def bug_goods(u_info, g_name):
    "用户购买商品"
    res =None
    g_name = str(g_name)
    if not g_name :
        print('购买商品名称不能为空！')
    else:
        goods_info = get_goods()
        for i in range(len(goods_info)):
            if goods_info[i]['p_name'] == g_name:
                if u_info['money'] < goods_info[i]['p_price']:
                    res = '余额不足购买商品失败！', goods_info[i]
                else:
                    new_money = u_info['money'] - goods_info[i]['p_price']
                    new_money =round(new_money,2)
                    my_sql_1 = "update userinfo set money = '%d' where u_id = '%d';"%(new_money,u_info['u_id'])
                    my_sql_2 = "INSERT INTO carts (u_id,p_id) VALUES('%d','%d');"%(u_info['u_id'],goods_info[i]['p_id'])
                    op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql_1)
                    op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql_2)
                    res = '购买商品成功！', goods_info[i]
        if not res:
            res = 'error ,购买商品%s不存在'% g_name
    return res

def get_carts_money(u_id):
    "查询用户购物车、余额"
    my_sql = "select u.money from userinfo u  where u.u_id ='%d';"% u_id
    u_money = op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql)
    my_sql = "select p.p_name from userinfo u ,carts c ,product p where u.u_id='%d'and u.u_id =c.u_id and c.p_id= p.p_id; "%u_id
    u_cart = op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql)
    return "账户余额：{m} 购物车：{c}".format(m =u_money,c =u_cart)

def add_goods(g_name, g_price):
    "添加商品"
    if not g_name:
        return 'error,添加商品失败，商品名称必须输入'
    price = round(float(g_price), 2)
    if price <= 0:
        return 'error,添加商品失败，商品价格须大于0'
    my_sql = "insert into product(p_name,p_price) values('%s','%s');"%(g_name,g_price)
    op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql)
    return 'success,添加商品：%s成功'% g_name

def recharge(u_id, amount):
    "输入用户ID给用户充值"
    u_id = int(u_id)
    u_amount = round(float(amount), 2)
    if u_amount <= 0:
        return 'error,充值金额须大于0'
    my_sql = "select u.u_name,u.money from userinfo u where u.u_id ='%d';" % u_id
    user_info = op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql)
    if len(user_info) == 0:
        return '用户id不存在'
    new_money = user_info[0]['money'] + u_amount
    my_sql = "update userinfo set money = '%d' where u_id = '%d';"%(new_money,u_id)
    op_mysql(host=HOST, user=USER, passwd=PASSWD, db=DB_NAME, sql=my_sql)
    return 'success,给用户:%s 充值%s 元 成功'% (user_info[0]['u_name'],u_amount)

menu.py 内容：

from lib.action import get_goods,bug_goods,get_carts_money,add_goods,recharge

def role_1(user):
    "普通用户菜单"
    choice = input('请输入你的选择：1：查看所有商品 2：购买商品 3：查看购物车和余额 4:退出\n').strip()
    if choice == '':
        print(get_goods())
    elif choice == '':
        goods_name = input("请输入要购买商品名称:\n").strip()
        print(bug_goods(user, goods_name))
    elif choice == '':
        print(get_carts_money(user['u_id']))
    elif choice == '':
        exit('退出程序')
    role_1(user)

def role_2(user):
    "管理员菜单"
    choice = input('请输入你的选择：1：添加商品 2：给用户充值 3：退出\n').strip()
    if choice == '':
        goods_name = input("请输入你要添加的商品名称：\n").strip()
        goods_price = input("请输入添加商品价格：\n").strip()
        print(add_goods(goods_name, goods_price))
    elif choice == '':
        u_id = input("请输入你要充值的用户id：\n").strip()
        amount = input("请输入充值金额：\n").strip()
        print(recharge(u_id, amount))
    elif choice == '':
        exit('退出程序')
    role_2(user)

bin 目录下存放启动文件：

start.py内容：

import os,sys
cur_path = os.path.abspath(__file__)
base_path = os.path.dirname(os.path.dirname(cur_path))
sys.path.insert(0,base_path)
from lib.action import login
from lib.menu import role_1,role_2

uName = input("请输入登录用户名：\n").strip()
uPass = input("请输入登录密码：\n").strip()
user = login(uName, uPass)
if user:  # 用户登录成功
    # 普通用户:
    if user['role'] == 1:
        role_1(user)
    # 管理员用户：
    elif user['role'] == 2:
        role_2(user)
    else:
        print("用户角色不存在")
else:
    print("用户尚未登录")

运行结果如下：