```markdown ### 代码概述 根据报告内容，生成符合该报告的Python代码，主要涉及数据库操作、业务逻辑处理以及用户界面设计。代码分为以下几个部分： 1. **数据库连接与操作**：使用`pyodbc`模块连接SQL Server数据库，实现对菜品、订单、用户等信息的CRUD操作。 2. **业务逻辑处理**：定义业务实体类（如`Dish`, `SetMeal`, `Ingredient`, `User`）和业务流程类（如`OrderManager`, `InventoryManager`），封装业务逻辑。 3. **用户界面设计**：使用`tkinter`模块构建图形用户界面，实现菜品管理、订单管理、用户管理等功能。 ### 代码解析 #### 1. 数据库连接与操作 ```python import pyodbc from datetime import datetime class DBConnection: _instance = None @staticmethod def get_instance(): if not DBConnection._instance: DBConnection._instance = DBConnection() return DBConnection._instance def __init__(self): self.conn = pyodbc.connect( 'DRIVER={SQL Server};SERVER=localhost;DATABASE=canteen_order_db;UID=sa;PWD=your_password' ) def execute_query(self, query, params=None): cursor = self.conn.cursor() if params: cursor.execute(query, params) else: cursor.execute(query) result = cursor.fetchall() cursor.close() return result def execute_non_query(self, query, params=None): cursor = self.conn.cursor() if params: cursor.execute(query, params) else: cursor.execute(query) self.conn.commit() cursor.close() def create_order_transaction(self, order_data, dish_ids, quantities): cursor = self.conn.cursor() try: self.conn.autocommit = False cursor.execute(""" INSERT INTO order_main (user_id, order_time, status, total_amount) VALUES (?, ?, ?, ?) """, ( order_data["user_id"], order_data["order_time"], order_data["status"], order_data["total_amount"] )) order_id = cursor.execute("SELECT SCOPE_IDENTITY()").fetchone()[0] for idx, dish_id in enumerate(dish_ids): cursor.execute(""" INSERT INTO order_detail (order_id, dish_id, quantity) VALUES (?, ?, ?) """, (order_id, dish_id, quantities[idx])) self.conn.commit() self.conn.autocommit = True return True except Exception as e: self.conn.rollback() self.conn.autocommit = True print(f"数据库事务失败：{e}") return False ``` #### 2. 业务逻辑处理 ```python from datetime import datetime, timedelta class Dish: def __init__(self, dish_id, dish_name, flavor, price, stock): self.dish_id = dish_id self.dish_name = dish_name self.flavor = flavor self.price = price self.stock = stock def deduct_stock(self, quantity): if self.stock >= quantity: self.stock -= quantity return True return False class SetMeal(Dish): def __init__(self, meal_id, meal_name, dish_ids, price): super().__init__(meal_id, meal_name, "", price, 0) self.dish_ids = dish_ids def calculate_price(self, dish_price_map): total = sum(dish_price_map.get(dish_id, 0) for dish_id in self.dish_ids) self.price = total return total class Ingredient: def __init__(self, ing_id, name, supplier, purchase_time, quantity, shelf_life): self.ing_id = ing_id self.name = name self.supplier = supplier self.purchase_time = purchase_time self.quantity = quantity self.shelf_life = shelf_life def is_expiring(self, days_threshold=3): expire_time = self.purchase_time + timedelta(days=self.shelf_life) return expire_time <= datetime.now() + timedelta(days=days_threshold) class OrderManager: def __init__(self): self.db_handler = DBConnection.get_instance() def create_order(self, user_id, dish_ids, quantities): total_amount = 0 dishes = self.db_handler.execute_query("SELECT * FROM dish_info") dish_map = {d[0]: Dish(*d) for d in dishes} for idx, dish_id in enumerate(dish_ids): dish = dish_map.get(dish_id) if not dish or not dish.deduct_stock(quantities[idx]): return "库存不足，下单失败" total_amount += dish.price * quantities[idx] order_data = { "user_id": user_id, "order_time": datetime.now(), "status": "已下单", "total_amount": total_amount } if self.db_handler.create_order_transaction(order_data, dish_ids, quantities): return "下单成功" return "下单失败，请重试" ``` #### 3. 用户界面设计 ```python import tkinter as tk from tkinter import ttk, messagebox class App: def __init__(self, root): self.root = root self.root.title("食堂管理系统") self.create_widgets() def create_widgets(self): # 菜品管理 dish_frame = ttk.LabelFrame(self.root, text="菜品管理") dish_frame.grid(row=0, column=0, padx=10, pady=10) # 添加菜品按钮 add_dish_button = ttk.Button(dish_frame, text="添加菜品", command=self.add_dish) add_dish_button.pack(pady=5) # 更多操作... # 订单管理 order_frame = ttk.LabelFrame(self.root, text="订单管理") order_frame.grid(row=0, column=1, padx=10, pady=10) # 创建订单按钮 create_order_button = ttk.Button(order_frame, text="创建订单", command=self.create_order) create_order_button.pack(pady=5) # 更多操作... # 用户管理 user_frame = ttk.LabelFrame(self.root, text="用户管理") user_frame.grid(row=1, column=0, padx=10, pady=10) # 添加用户按钮 add_user_button = ttk.Button(user_frame, text="添加用户", command=self.add_user) add_user_button.pack(pady=5) # 更多操作... def add_dish(self): # 弹出添加菜品窗口 add_dish_window = tk.Toplevel(self.root) add_dish_window.title("添加菜品") # 输入框... # 提交按钮... def create_order(self): # 弹出创建订单窗口 create_order_window = tk.Toplevel(self.root) create_order_window.title("创建订单") # 输入框... # 提交按钮... def add_user(self): # 弹出添加用户窗口 add_user_window = tk.Toplevel(self.root) add_user_window.title("添加用户") # 输入框... # 提交按钮... if __name__ == "__main__": root = tk.Tk() app = App(root) root.mainloop() ``` ### 知识点 1. **数据库连接与操作**：使用`pyodbc`模块连接SQL Server数据库，实现对菜品、订单、用户等信息的CRUD操作。确保数据一致性，使用事务处理。 2. **面向对象编程**：通过定义业务实体类和业务流程类，封装业务逻辑，实现代码复用和模块化设计。 3. **图形用户界面设计**：使用`tkinter`模块构建图形用户界面，实现用户交互，提升用户体验。 ```