Flask sqlAlchemy

Import the necessary modules

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

Create a Flask application

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///example.db'  # Specify the database URI
db = SQLAlchemy(app)  # Initialize SQLAlchemy

Define the User model

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(20), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    image_file = db.Column(db.String(20), nullable=False, default='default.jpg')
    password = db.Column(db.String(60), nullable=False)
    posts = db.relationship('Post', backref='author', lazy=True)

    def __repr__(self):
        return f'User {self.username} - {self.email}'

Define the Post model

class Post(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(100), unique=True, nullable=False)
    date_posted = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)
    content = db.Column(db.Text, nullable=False)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)

    def __repr__(self):
        return f'Post {self.title} - {self.date_posted}'

Add a new user to the database in python console

new_user = User(username='JohnDoe', email='johndoe@example.com', password='password')
db.session.add(new_user)
db.session.commit()

Add a new post associated with the user to the database in python console

new_post = Post(title='First Post', content='Hello World!', user_id=new_user.id)
db.session.add(new_post)
db.session.commit()

Add user and post from route

@app.route('/create-user')
def create_user():
    # Add a new user to the database
    new_user = User(username='JohnDoe', email='johndoe@example.com', password='password')
    db.session.add(new_user)
    db.session.commit()

    # Add a new post associated with the user to the database
    new_post = Post(title='First Post', content='Hello World!', user_id=new_user.id)
    db.session.add(new_post)
    db.session.commit()
    return redirect('/')

see full code