crud.py

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

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////tmp/test.db'
db = SQLAlchemy(app)

class Post(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(80), nullable=False)
    content = db.Column(db.Text, nullable=False)

@app.route('/')
def index():
    posts = Post.query.all()
    return render_template('index.html', posts=posts)

@app.route('/post/<int:post_id>')
def post(post_id):
    post = Post.query.get(post_id)
    if post is None:
        return redirect(url_for('index'))
    return render_template('post.html', post=post)

@app.route('/post/create', methods=('GET', 'POST'))
def create():
    if request.method == 'POST':
        title = request.form['title']
        content = request.form['content']
        post = Post(title=title, content=content)
        db.session.add(post)
        db.session.commit()
        return redirect(url_for('index'))
    return render_template('create.html')

@app.route('/post/<int:post_id>/update', methods=('GET', 'POST'))
def update(post_id):
    post = Post.query.get(post_id)
    if post is None:
        return redirect(url_for('index'))
    if request.method == 'POST':
        post.title = request.form['title']
        post.content = request.form['content']
        db.session.commit()
        return redirect(url_for('post', post_id=post_id))
    return render_template('update.html', post=post)

@app.route('/post/<int:post_id>/delete', methods=('POST',))
def delete(post_id):
    post = Post.query.get(post_id)
    if post is None:
        return redirect(url_for('index'))
    db.session.delete(post)
    db.session.commit()
    return redirect(url_for('index'))

if __name__ == '__main__':
    with app.app_context():
        db.create_all()
    app.run(debug=True)