下面给你一个基于 Python + MySQL 的简易餐厅点餐系统示例，适合课程设计 / 练手项目。特点是：结构清晰、代码少、易扩展。

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一、功能设计（简易版）

✅ 菜品管理（增删查）

✅ 顾客下单

✅ 订单查看

✅ 订单结算

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二、数据库设计（MySQL）

1️⃣ 创建数据库

CREATE DATABASE restaurant DEFAULT CHARSET utf8mb4;
USE restaurant;

2️⃣ 菜品表 dishes

CREATE TABLE dishes (
    id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(50) NOT NULL,
    price DECIMAL(6,2) NOT NULL,
    stock INT DEFAULT 100
);

3️⃣ 订单表 orders

CREATE TABLE orders (
    id INT PRIMARY KEY AUTO_INCREMENT,
    table_no INT NOT NULL,
    total_price DECIMAL(8,2),
    create_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

4️⃣ 订单明细表 order_items

CREATE TABLE order_items (
    id INT PRIMARY KEY AUTO_INCREMENT,
    order_id INT,
    dish_id INT,
    quantity INT,
    FOREIGN KEY (order_id) REFERENCES orders(id),
    FOREIGN KEY (dish_id) REFERENCES dishes(id)
);

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三、Python 环境准备

pip install pymysql

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四、Python 连接 MySQL

db.py

import pymysql

def get_conn():
    return pymysql.connect(
        host="localhost",
        user="root",
        password="123456",   # 改成你的密码
        database="restaurant",
        charset="utf8mb4",
        cursorclass=pymysql.cursors.DictCursor
    )

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五、核心功能实现

1️⃣ 显示菜单

from db import get_conn

def show_menu():
    conn = get_conn()
    with conn.cursor() as cursor:
        cursor.execute("SELECT * FROM dishes")
        dishes = cursor.fetchall()
        print("\n===== 菜品列表 =====")
        for d in dishes:
            print(f"{d['id']}. {d['name']} ￥{d['price']} 库存:{d['stock']}")
    conn.close()

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2️⃣ 下单功能

def create_order(table_no):
    conn = get_conn()
    try:
        with conn.cursor() as cursor:
            cursor.execute(
                "INSERT INTO orders (table_no) VALUES (%s)",
                (table_no,)
            )
            order_id = cursor.lastrowid

            while True:
                show_menu()
                dish_id = input("输入菜品ID（0结束）：")
                if dish_id == "0":
                    break
                qty = int(input("数量："))

                cursor.execute(
                    "SELECT price, stock FROM dishes WHERE id=%s",
                    (dish_id,)
                )
                dish = cursor.fetchone()

                if not dish or dish["stock"] < qty:
                    print("库存不足")
                    continue

                cursor.execute(
                    "INSERT INTO order_items (order_id,dish_id,quantity) "
                    "VALUES (%s,%s,%s)",
                    (order_id, dish_id, qty)
                )

                cursor.execute(
                    "UPDATE dishes SET stock=stock-%s WHERE id=%s",
                    (qty, dish_id)
                )

        conn.commit()
        calc_total(order_id)
        print("下单成功")
    finally:
        conn.close()

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3️⃣ 计算订单总价

def calc_total(order_id):
    conn = get_conn()
    with conn.cursor() as cursor:
        sql = """
        SELECT SUM(d.price*i.quantity) total
        FROM order_items i
        JOIN dishes d ON i.dish_id=d.id
        WHERE i.order_id=%s
        """
        cursor.execute(sql, (order_id,))
        total = cursor.fetchone()["total"]
        cursor.execute(
            "UPDATE orders SET total_price=%s WHERE id=%s",
            (total, order_id)
        )
    conn.commit()
    conn.close()

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4️⃣ 查看订单

def show_orders():
    conn = get_conn()
    with conn.cursor() as cursor:
        cursor.execute("""
        SELECT o.id,o.table_no,o.total_price,o.create_time,
               d.name,i.quantity
        FROM orders o
        JOIN order_items i ON o.id=i.order_id
        JOIN dishes d ON i.dish_id=d.id
        ORDER BY o.id DESC
        """)
        for row in cursor.fetchall():
            print(row)
    conn.close()

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六、主程序入口

main.py

from order import create_order, show_orders
from menu import show_menu

def main():
    while True:
        print("\n1. 查看菜单")
        print("2. 点餐")
        print("3. 查看订单")
        print("0. 退出")
        choice = input("选择：")

        if choice == "1":
            show_menu()
        elif choice == "2":
            table = int(input("桌号："))
            create_order(table)
        elif choice == "3":
            show_orders()
        elif choice == "0":
            break

if __name__ == "__main__":
    main()

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七、运行效果示例

===== 菜品列表 =====
1. 鱼香肉丝 ￥18.00 库存:50
2. 宫保鸡丁 ￥22.00 库存:40

输入菜品ID（0结束）：1
数量：2
下单成功

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八、可扩展方向（加分项）

✅ 管理员登录

✅ 图形界面（Tkinter / PyQt）

✅ Web 版（Flask / Django）

✅ 支付模拟

✅ 报表统计（日营业额）