models.py

from flask import Flask, render_template
from flask_sqlalchemy import SQLAlchemy
from flask_sqlalchemy import Model
from flask_login import LoginManager, UserMixin
from sqlalchemy.orm import relationship

app =  Flask(__name__)
db = SQLAlchemy(app)


login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'login'
     
class User(UserMixin, db.Model):
    """User model"""

    __tablename__ = "users"

    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(25), unique=True, nullable=False)
    password = db.Column(db.String(), nullable=False)
    email = db.Column(db.String(), unique=True, nullable=False)
    #authenticated = db.Column(db.Boolean, default=False)

    reviews = relationship('Reviews', backref='users', lazy='dynamic')
        

class Books(db.Model):
    __tablename__ = "books"

    id = db.Column(db.Integer, primary_key=True)
    isbn = db.Column(db.String(50))
    title = db.Column(db.Text)
    author = db.Column(db.Text)
    year = db.Column(db.String(50))

    reviews = relationship('Reviews', backref='books', lazy='dynamic')
    

class Reviews(db.Model):
    __tablename__ = "reviews"

    id = db.Column(db.Integer, primary_key=True)
    users_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
    books_id = db.Column(db.Integer, db.ForeignKey('books.id'), nullable=False)
    comment = db.Column(db.Text, nullable=False)
    rating = db.Column(db.Integer)