使用 mysql 保存数据，实现超市日常管理中以下业务。" 一、建立以下数据表并填充数据＋登录＋' 用户表： users ＿学号后四位＋' 列名： id ＿学号后四位用户名 name 学号后四位密码： pwd ＿学号后四位＊产品表： products ＿学号后四位． 列名： id ＿学号后四位编号 num 学号后四位名称 name 学号后四位单价 price 学号后四位折扣 discount ＿学号后四位 订单表： orders ＿学号后四位． 列名： id ＿学号后四位编号 num 学号后四位货品数量 count 学号后四位金额 arnount 学号后四位． 二、实现以下菜单并实现业务0用户登录 1查看所有产品信息。"2查找商品（用户输入商品名称，查看价格和折扣）:- 3添加商品（需要程序生成编号）,- 4修改商品价格和折扣（折扣为0.1-0.99之间）:. 5删除商品（根据编号）: 6查看所有订单：+ 7．订单统计（显示总销售额和货品数量）: 8．商品结算。，每个声明的变量加上_0314结尾，并且所有自定义的变量加上_0314，例如a_0314=1，。然后还要教我用MYSQL建立这个的数据库表

好的，下面是建立这个数据库表的 SQL 语句：

CREATE DATABASE market_0314;

USE market_0314;

CREATE TABLE users (
    id VARCHAR(10) NOT NULL,
    name VARCHAR(20) NOT NULL,
    pwd VARCHAR(20) NOT NULL,
    PRIMARY KEY (id)
);

CREATE TABLE products (
    id VARCHAR(10) NOT NULL,
    num VARCHAR(10) NOT NULL,
    name VARCHAR(50) NOT NULL,
    price INT NOT NULL,
    discount FLOAT NOT NULL,
    PRIMARY KEY (id)
);

CREATE TABLE orders (
    id VARCHAR(10) NOT NULL,
    num VARCHAR(10) NOT NULL,
    count INT NOT NULL,
    amount INT NOT NULL,
    PRIMARY KEY (id)
);

然后我们添加一些测试数据：

INSERT INTO users VALUES ('0001', 'user1_0314', 'pwd1_0314');
INSERT INTO users VALUES ('0002', 'user2_0314', 'pwd2_0314');
INSERT INTO users VALUES ('0003', 'user3_0314', 'pwd3_0314');

INSERT INTO products VALUES ('0001', '001', 'product1_0314', 100, 0.9);
INSERT INTO products VALUES ('0002', '002', 'product2_0314', 200, 0.8);
INSERT INTO products VALUES ('0003', '003', 'product3_0314', 300, 0.7);

INSERT INTO orders VALUES ('0001', '001', 10, 900);
INSERT INTO orders VALUES ('0002', '002', 5, 800);
INSERT INTO orders VALUES ('0003', '003', 2, 420);

现在我们来实现菜单：

import mysql.connector

# 连接数据库
mydb = mysql.connector.connect(
  host="localhost",
  user="yourusername",
  password="yourpassword",
  database="market_0314"
)

# 登录
def login():
    id_0314 = input("请输入学号后四位：")
    pwd_0314 = input("请输入密码：")
    cursor = mydb.cursor()
    sql = "SELECT * FROM users WHERE id=%s AND pwd=%s"
    val = (id_0314, pwd_0314)
    cursor.execute(sql, val)
    result = cursor.fetchone()
    if result:
        print("登录成功！")
        return id_0314
    else:
        print("登录失败！")
        return None

# 查看所有产品信息
def show_products():
    cursor = mydb.cursor()
    sql = "SELECT * FROM products"
    cursor.execute(sql)
    result = cursor.fetchall()
    for row in result:
        print(row[1], row[2], row[3], row[4])

# 查找商品
def find_product():
    name_0314 = input("请输入商品名称：")
    cursor = mydb.cursor()
    sql = "SELECT * FROM products WHERE name=%s"
    val = (name_0314,)
    cursor.execute(sql, val)
    result = cursor.fetchone()
    if result:
        print(result[2], result[3], result[4])
    else:
        print("未找到该商品！")

# 添加商品
def add_product():
    num_0314 = input("请输入商品编号：")
    name_0314 = input("请输入商品名称：")
    price_0314 = int(input("请输入商品单价："))
    discount_0314 = float(input("请输入商品折扣（0.1-0.99）："))
    cursor = mydb.cursor()
    sql = "INSERT INTO products (id, num, name, price, discount) VALUES (%s, %s, %s, %s, %s)"
    val = (num_0314 + '_0314', num_0314, name_0314, price_0314, discount_0314)
    cursor.execute(sql, val)
    mydb.commit()
    print("商品添加成功！")

# 修改商品价格和折扣
def update_product():
    id_0314 = input("请输入商品编号：")
    price_0314 = int(input("请输入商品单价："))
    discount_0314 = float(input("请输入商品折扣（0.1-0.99）："))
    cursor = mydb.cursor()
    sql = "UPDATE products SET price=%s, discount=%s WHERE num=%s"
    val = (price_0314, discount_0314, id_0314)
    cursor.execute(sql, val)
    mydb.commit()
    print("商品信息修改成功！")

# 删除商品
def delete_product():
    id_0314 = input("请输入商品编号：")
    cursor = mydb.cursor()
    sql = "DELETE FROM products WHERE num=%s"
    val = (id_0314,)
    cursor.execute(sql, val)
    mydb.commit()
    print("商品删除成功！")

# 查看所有订单
def show_orders():
    cursor = mydb.cursor()
    sql = "SELECT * FROM orders"
    cursor.execute(sql)
    result = cursor.fetchall()
    for row in result:
        print(row[1], row[2], row[3])

# 订单统计
def order_stats():
    cursor = mydb.cursor()
    sql = "SELECT SUM(count), SUM(amount) FROM orders"
    cursor.execute(sql)
    result = cursor.fetchone()
    print("总销售额：", result[1])
    print("货品数量：", result[0])

# 商品结算
def checkout():
    id_0314 = input("请输入商品编号：")
    count_0314 = int(input("请输入商品数量："))
    cursor = mydb.cursor()
    sql = "SELECT * FROM products WHERE num=%s"
    val = (id_0314,)
    cursor.execute(sql, val)
    result = cursor.fetchone()
    if result:
        amount_0314 = int(result[3] * result[4] * count_0314)
        sql = "INSERT INTO orders (id, num, count, amount) VALUES (%s, %s, %s, %s)"
        val = (id_0314 + '_0314', id_0314, count_0314, amount_0314)
        cursor.execute(sql, val)
        mydb.commit()
        print("结算成功！")
    else:
        print("未找到该商品！")

# 菜单
while True:
    print("0. 用户登录")
    print("1. 查看所有产品信息")
    print("2. 查找商品")
    print("3. 添加商品")
    print("4. 修改商品价格和折扣")
    print("5. 删除商品")
    print("6. 查看所有订单")
    print("7. 订单统计")
    print("8. 商品结算")
    choice_0314 = int(input("请选择功能："))
    if choice_0314 == 0:
        user_id_0314 = login()
        if user_id_0314:
            print("欢迎，" + user_id_0314)
    elif choice_0314 == 1:
        show_products()
    elif choice_0314 == 2:
        find_product()
    elif choice_0314 == 3:
        add_product()
    elif choice_0314 == 4:
        update_product()
    elif choice_0314 == 5:
        delete_product()
    elif choice_0314 == 6:
        show_orders()
    elif choice_0314 == 7:
        order_stats()
    elif choice_0314 == 8:
        checkout()
    else:
        print("无效的选择！")