models.py

import os
from sqlalchemy import Date
from flask_sqlalchemy import SQLAlchemy
import json
from flask_migrate import Migrate

database_path = os.environ.get('DATABASE_URL')
if database_path.startswith('postgres://'):
    database_path = database_path.replace('postgres://', 'postgresql://', 1)

db = SQLAlchemy()

# binds sqlalchemy service to app
def setup_db(app, database_path=database_path):
    app.config["SQLALCHEMY_DATABASE_URI"] = database_path
    app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
    db.app = app
    db.init_app(app)
    #migrate = Migrate(app, db)
    with app.app_context():
        db.create_all()

# third table
movie_items = db.Table('movie_items',
    db.Column('movie_id', db.Integer, db.ForeignKey('movie.id')),
    db.Column('actor_id', db.Integer, db.ForeignKey('actor.id'))
)

def weCommit(p):
    db.session.add(p)
    db.session.commit()

class Movie(db.Model):
    __tablename__ = 'movie'
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String, nullable=False, unique=True)
    release_date = db.Column(db.String, nullable=True)
    actors = db.relationship('Actor', secondary=movie_items, backref=db.backref('movies', lazy=True))

    def __init__(self, title, release_date):
        self.title = title
        self.release_date = release_date

    def insert(self):
        db.session.add(self)
        db.session.commit()

    def update(self):
        db.session.commit()
    
    def delete(self):
        db.session.delete(self)
        db.session.commit()

    def format(self):
        return {
            'id': self.id,
            'title': self.title,
            'release_date': self.release_date
        }


class Actor(db.Model):
    __tablename__ = 'actor'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String, nullable=False)
    age = db.Column(db.Integer, nullable=True)
    gender = db.Column(db.String, nullable=True)

    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.gender = gender

    def insert(self):
        db.session.add(self)
        db.session.commit()

    def update(self):
        db.session.commit()
    
    def delete(self):
        db.session.delete(self)
        db.session.commit()

    def format(self):
        return {
            'id': self.id,
            'name': self.name,
            'age': self.age,
            'gender': self.gender
        }