Flask简单实例-5

最新推荐文章于 2025-05-04 10:02:35 发布

Pineapple丶

最新推荐文章于 2025-05-04 10:02:35 发布

阅读量752

点赞数

分类专栏： Flask

本文链接：https://blog.youkuaiyun.com/weixin_44930101/article/details/90179357

版权

Flask 专栏收录该内容

12 篇文章

订阅专栏

本文介绍了使用Flask框架创建简单web应用的步骤，包括定义路由、创建视图函数以及运行服务器。通过实例展示了如何快速搭建一个Hello, World!的网页。" 114463257,10544867,Java中使用SparkLauncher提交Spark应用,"['Spark提交', 'Java开发', 'Spark集群']

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

在这里插入图片描述

# py

from flask import Flask, render_template, request, redirect, url_for, flash, session
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)

app.config.from_object('setting')

db = SQLAlchemy(app=app)


''' 创建表 '''
class Books(db.Model):
    id = db.Column(db.Integer, primary_key=True, comment='书籍ID')
    name = db.Column(db.String(30), unique=True, comment='书籍名称')
    price = db.Column(db.DECIMAL, comment='书籍价格')


# 首页【所有书籍】
@app.route('/')
def index():
    books = Books.query.order_by(Books.price.desc()).all()
    return render_template('index.html', books=books)


# 添加书籍（方法一）
@app.route('/add_book', methods=['GET', 'POST'])
def add_book():
    if request.method == 'POST':
        name = request.form.get('name')
        price = request.form.get('price')
        new_name = Books(name=name, price=price)
        try:
            db.session.add(new_name)
            db.session.commit()
            flash('添加书籍成功!')
        except Exception:
            flash('添加失败（书籍名称重名或其他）')
        # return redirect(url_for('index'))
    return render_template('add_book.html')

# 添加书籍（方法二：过滤器）
# @app.route('/add_book', methods=['GET','POST'])
# def add_book():
#     if request.method == 'POST':
#         name = request.form.get('name')
#         price = request.form.get('price')
#         one_book = Books.query.filter(Books.name==name).first()
#         if one_book:
#             return '已经存在'
#         new_book = Books(name=name, price=price)
#         db.session.add(new_book)
#         db.session.commit()
#         return redirect(url_for('index'))
#     return render_template('add_book.html')


# 修改书籍
@app.route('/alter_book', methods=['GET','POST'])
def alter_book():
    book_id = request.args.get('book_id')
    one_book = Books.query.get(book_id)
    if request.method == 'POST':
        new_book = request.form.get('name')
        one_book.name = new_book
        db.session.add(one_book)
        db.session.commit()
        return redirect(url_for('index'))
    return render_template('alter_book.html', one_book=one_book)


# 购买书籍
@app.route('/buy_book')
def buy_book():
    if session.get('user_id'):
        return '可以购买'
    else:
        return '需要登录'


if __name__ == '__main__':

    # db.drop_all()
    # db.create_all()

    app.run()

# setting

DEBUG = True                # 开启调试模式
SECRET_KEY = "962464"       # 随机输入字符串
# SQLALCHEMY_DATABASE_URI = 链接的数据库类型+使用的驱动://用户名:密码@数据库地址:端口/数据库名称?数据库编码
SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root:mysql@127.0.0.1:3306/exam5?charset=utf8' # 连接数据库
# SQLALCHEMY_ECHO = True      # 在控制面板显示
SQLALCHEMY_TRACK_MODIFICATIONS = False

{# base.html #}

{% block top %}
    <a href="{{ url_for('index') }}">首页【所有书籍】</a>
    <a href="{{ url_for('add_book') }}">添加书籍</a>
{% endblock top %}

{% block content %}

{% endblock content %}

{# index.html #}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>所有书籍</title>
</head>
<body>
    {% extends 'base.html' %}

    {% block content %}
        <table border="1" cellspacing="0">
            <tr>
                <td>书籍ID</td>
                <td>名称</td>
                <td>价格</td>
                <td>操作</td>
            </tr>
            {% for book in books %}
                <tr>
                    <td>{{ book.id }}</td>
                    <td>{{ book.name }}</td>
                    <td>{{ book.price }}</td>
                    <td>
                        <a href="{{ url_for('buy_book', book_id = book.id) }}">购买</a> |
                        <a href="{{ url_for('alter_book', book_id = book.id) }}">修改书籍：{{ book.name }}</a> |
                    </td>
                </tr>
            {% endfor %}
        </table>
    {% endblock content %}
</body>
</html>

{# add_book.html #}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>添加书籍</title>
</head>
<body>
    {% extends 'base.html' %}

    {% block content %}
        <form action="" method="post">
            添加书籍：<input type="text" name="name" value="">
            书籍价格：<input type="text" name="price" value="">
            <input type="submit" value="确认添加">
        </form>
        {% for message in get_flashed_messages() %}
            {{ message }}
        {% endfor %}
    {% endblock content %}
</body>
</html>

{# alter_book.html #}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>修改书籍</title>
</head>
<body>
    {% extends 'base.html' %}

    {% block content %}
        <form action="" method="post">
            修改书籍：<input type="text" name="name" value="" placeholder="{{ one_book.name }}">
            <input type="submit" value="确认修改">
        </form>
    {% endblock content %}
</body>
</html>