app.py

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

app = Flask(__name__)
basedir = os.path.abspath(os.path.dirname(__file__))
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'instance', 'test.db')
db = SQLAlchemy(app)

class Todo(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    content = db.Column(db.String(200), nullable=False)
    date_created=db.Column(db.DateTime, default=datetime.utcnow)

    def __repr__(self):
        return '<Task %r>' % self.id


@app.route('/', methods=['POST', 'GET'])
def index():
    if request.method=='POST':
        task_content = request.form['content']
        new_task = Todo(content=task_content)

        try:
            db.session.add(new_task)
            db.session.commit()
            return redirect('/')
        except:
            return 'There was an issue adding your task'
    else:
        tasks = Todo.query.order_by(Todo.date_created).all()
        return render_template('index.html', tasks=tasks)
    

@app.route('/delete/<int:id>')
def delete(id):
    task_to_delete = Todo.query.get_or_404(id)

    try:
        db.session.delete(task_to_delete)
        db.session.commit()
        return redirect('/')
    except:
        return 'There was an issue deleting the task'
    
@app.route('/update/<int:id>', methods=['GET', 'POST'])
def update(id):
    task = Todo.query.get_or_404(id)
    if request.method=='POST':
        task.content = request.form['content']
        try:
            db.session.commit()
            return redirect('/')
        except:
            return 'There was an issue updating the task'
    else:
        return render_template('update.html', task=task)

if __name__== "__main__":
    app.run(debug=True)