app.py

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

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

class Todo(db.Model):
    id=db.Column(db.Integer, primary_key=True)
    contents=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":
        content=request.form['content']
        new_task=Todo(contents=content)
        try:
            db.session.add(new_task)
            db.session.commit()
            return redirect('/')
        except:
            return "An error occured"
    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=Todo.query.get_or_404(id)

    try:
        db.session.delete(task)
        db.session.commit()
        return redirect('/')
    except:
        return "An error occured"


@app.route('/update/<int:id>', methods=['POST','GET'])
def upadte(id):
    task= Todo.query.get_or_404(id)
    
    if request.method=="POST":
        task.contents=request.form['content']
        try:
            db.session.commit()
            return redirect('/')
        except:
            return "An error Occured"
    else:
        return render_template('update.html', task=task)
 
if __name__=="__main__":
    app.run(debug=True)