Flask & SQL Alchemy Not Working ((OperationalError) no such table:)

Python parses your file and executes every line (it's more complex I guess but whatever). So it gets to the following line (which is executed before if __name__ == "__main__": ...:

db.session.commit()

It tries to add User x to the database. But the database/table does not exist yet because you try to create it a couple of lines later by calling init.db(), which is wrong by the way. What is init? It's nowhere defined in your code.

Please read this carefully again

Here is what your code should look like:

from flask import Flaskfrom flask.ext.sqlalchemy import SQLAlchemyapp = Flask(__name__)app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///test.db"db = SQLAlchemy(app)class User(db.Model):    id = db.Column(db.Integer, primary_key=True)    username = db.Column(db.String(80), unique=True)    email = db.Column(db.String(120), unique=True)    def __init__(self, username, email):        self.username = username        self.email = email    def __repr__(self):        return "<User %r>" % self.username@app.route("/")def index():    return User.query.all() # I don't think this will workif __name__ == "__main__":    db.create_all()    x = User("test", "test@gmail.com")    db.session.add(x)    db.session.commit()    app.run(debug=True)

Note that db.create_all() will fail and crash if the database already exists. Have a look at Flask-Script. It can help you building a setup script for your app.