如何利用MySQL和Python开发一个简单的在线订餐系统
随着互联网的快速发展,越来越多的人选择在线订餐来解决日常的饮食需求。为了满足用户的需求,许多公司开发了各式各样的在线订餐系统。本文将介绍如何使用MySQL和Python来开发一个简单的在线订餐系统,并提供具体的代码示例。
首先,我们需要创建一个MySQL数据库来存储菜单信息、用户信息以及订单信息。可以使用以下SQL语句创建相应的表:
CREATE TABLE IF NOT EXISTS `menu` ( `id` INT AUTO_INCREMENT PRIMARY KEY, `name` VARCHAR(100) NOT NULL, `price` DECIMAL(10,2) NOT NULL ); CREATE TABLE IF NOT EXISTS `users` ( `id` INT AUTO_INCREMENT PRIMARY KEY, `username` VARCHAR(100) NOT NULL, `password` VARCHAR(100) NOT NULL ); CREATE TABLE IF NOT EXISTS `orders` ( `id` INT AUTO_INCREMENT PRIMARY KEY, `user_id` INT NOT NULL, `menu_id` INT NOT NULL, `quantity` INT NOT NULL, `date` DATE NOT NULL );
接下来,我们使用Python和MySQL连接库来实现数据库的连接和操作。以下是MySQL连接的代码示例:
import mysql.connector # 连接MySQL数据库 def connect_db(): conn = mysql.connector.connect( host="localhost", user="your_username", password="your_password", database="your_database" ) return conn # 查询菜单 def get_menu(): conn = connect_db() cursor = conn.cursor() cursor.execute("SELECT * FROM menu") menu = cursor.fetchall() cursor.close() conn.close() return menu # 用户注册 def register(username, password): conn = connect_db() cursor = conn.cursor() cursor.execute("INSERT INTO users (username, password) VALUES (%s, %s)", (username, password)) conn.commit() cursor.close() conn.close() # 用户登录 def login(username, password): conn = connect_db() cursor = conn.cursor() cursor.execute("SELECT * FROM users WHERE username = %s AND password = %s", (username, password)) user = cursor.fetchone() cursor.close() conn.close() return user # 下订单 def place_order(user_id, menu_id, quantity, date): conn = connect_db() cursor = conn.cursor() cursor.execute("INSERT INTO orders (user_id, menu_id, quantity, date) VALUES (%s, %s, %s, %s)", (user_id, menu_id, quantity, date)) conn.commit() cursor.close() conn.close()
现在我们已经可以从数据库中查询菜单、实现用户注册和登录以及下订单了。
为了让用户能够使用在线订餐系统,我们需要一个简单的用户界面。以下是使用Python的Flask库来实现一个简单的网页界面的代码示例:
from flask import Flask, render_template, request app = Flask(__name__) # 用户界面 @app.route("/") def index(): menu = get_menu() return render_template("index.html", menu=menu) # 用户注册 @app.route("/register", methods=["GET", "POST"]) def register_page(): if request.method == "POST": username = request.form["username"] password = request.form["password"] register(username, password) return render_template("success.html") return render_template("register.html") # 用户登录 @app.route("/login", methods=["GET", "POST"]) def login_page(): if request.method == "POST": username = request.form["username"] password = request.form["password"] user = login(username, password) if user: return render_template("success.html") else: return render_template("login.html", error="Invalid username or password.") return render_template("login.html") # 下订单 @app.route("/place_order", methods=["POST"]) def place_order_page(): user_id = request.form["user_id"] menu_id = request.form["menu_id"] quantity = request.form["quantity"] date = request.form["date"] place_order(user_id, menu_id, quantity, date) return render_template("success.html") if __name__ == "__main__": app.run()
上述代码创建了一个基于Flask的简易网页界面,包括主页、用户注册页、用户登录页和下订单页。
最后,我们需要创建相应的html模板文件来呈现网页界面。以下是一个简单的示例:
index.html:
<!DOCTYPE html> <html> <head> <title>Online Ordering System</title> </head> <body> {% for item in menu %} <h3>{{ item[1] }}</h3> <p>Price: {{ item[2] }}</p> <form action="/place_order" method="post"> <input type="hidden" name="user_id" value="1"> <input type="hidden" name="menu_id" value="{{ item[0] }}"> <input type="number" name="quantity" min="1" max="10" placeholder="Quantity" required> <input type="date" name="date" required> <button type="submit">Order</button> </form> <hr> {% endfor %} </body> </html>
register.html:
<!DOCTYPE html> <html> <head> <title>User Registration</title> </head> <body> <h2>User Registration</h2> <form action="/register" method="post"> <input type="text" name="username" placeholder="Username" required> <input type="password" name="password" placeholder="Password" required> <button type="submit">Register</button> </form> </body> </html>
login.html:
<!DOCTYPE html> <html> <head> <title>User Login</title> </head> <body> <h2>User Login</h2> {% if error %} <p style="color:red;">{{ error }}</p> {% end %} <form action="/login" method="post"> <input type="text" name="username" placeholder="Username" required> <input type="password" name="password" placeholder="Password" required> <button type="submit">Login</button> </form> </body> </html>
success.html:
<!DOCTYPE html> <html> <head> <title>Success</title> </head> <body> <h2>Success</h2> <p>Your order has been placed successfully.</p> </body> </html>
以上就是如何利用MySQL和Python开发一个简单的在线订餐系统的详细代码示例。通过参考该示例,您可以进一步扩展和优化您的在线订餐系统,以适应实际需求。
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