model.py

from datetime import datetime
import os
from flask import Flask
from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()


class Reservation(db.Model):
    __tablename__ = "reservations"

    reservation_id = db.Column(db.Integer, autoincrement=True, primary_key=True)
    username = db.Column(db.String)
    start_time = db.Column(db.DateTime(timezone=True))

    def __repr__(self):
        return f"<User username={self.username} start_time={self.start_time}>"

    def to_dict(self):
        return {
            "reservation_id": self.reservation_id,
            "username": self.username,
            "start_time": self.start_time.isoformat(),
        }

def connect_to_db(flask_app, echo = False):
    db_uri = os.environ["DATABASE_URL"].replace("postgres", "postgresql")
    flask_app.config["SQLALCHEMY_DATABASE_URI"] = db_uri
    flask_app.config["SQLALCHEMY_ECHO"] = echo
    flask_app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False

    db.app = flask_app
    db.init_app(flask_app)

    print("Connected to the db!")


if __name__ == "__main__":
    app = Flask(__name__)
    connect_to_db(app, True)