[FIXED] Flask : sqlalchemy.exc.ProgrammingError: (psycopg2.ProgrammingError) relation "users" does not exist

Issue

I am working on a flask app based on http://code.tutsplus.com/tutorials/intro-to-flask-signing-in-and-out--net-29982.

As part of the tut I'm trying to connect to a postgres server, with a structure as in the screenshot. I've added a db 'flask' which you can see.

Based on the tut I have the following code in my main file ('routes.py'):

from flask.ext.sqlalchemy import SQLAlchemy

from flask import Flask

app = Flask(__name__)

app.config['SQLALCHEMY_DATABASE_URI'] = "postgresql://postgres:123@localhost/flask"

db = SQLAlchemy(app)
from models import User
# db.init_app(app)
db.create_all()
db.session.commit()


admin = User('admin', '[email protected]', 'admin1', '[email protected]')
guest = User('admi2', '[email protected]', 'admin', '[email protected]')
# guest = User('guest', '[email protected]')
db.session.add(admin)
db.session.add(guest)
db.session.commit()

models.py:

from flask.ext.sqlalchemy import SQLAlchemy
from werkzeug import generate_password_hash, check_password_hash

db = SQLAlchemy()

class User(db.Model):
  __tablename__ = 'users'
  uid = db.Column(db.Integer, primary_key = True)
  firstname = db.Column(db.String(100))
  lastname = db.Column(db.String(100))
  email = db.Column(db.String(120), unique=True)
  pwdhash = db.Column(db.String(54))

  def __init__(self, firstname, lastname, email, password):
    self.firstname = firstname.title()
    self.lastname = lastname.title()
    self.email = email.lower()
    self.set_password(password)

  def set_password(self, password):
    self.pwdhash = generate_password_hash(password)

  def check_password(self, password):
    return check_password_hash(self.pwdhash, password)

When run the debugger gives:

sqlalchemy.exc.ProgrammingError: (psycopg2.ProgrammingError) relation "users" does not exist
LINE 1: INSERT INTO users (firstname, lastname, email, pwdhash) VALU...
                    ^
 [SQL: 'INSERT INTO users (firstname, lastname, email, pwdhash) VALUES (%(firstname)s, %(lastname)s, %(email)s, %(pwdhash)s) RETURNING users.uid'] [parameters: {'lastname': '[email protected]', 'firstname': 'Admin', 'pwdhash': 'pbkdf2:sha1:1000$eZvJNKHO$64f59c34364e3d6094d126fa3ca2b327ab39e302', 'email': 'admin1'}]

What am I doing wrong?

Solution

You're initializing your database twice.

I'd suggest taking a good look at this: http://flask.pocoo.org/docs/0.10/patterns/sqlalchemy/

Essentially, you'll want to split things up into a few more files to prevent import issues and make things a little more clean. I've done the below which seems to work. Note, I've used SQLite, since I do not have Postgres installed on this box.

app.py

from flask import Flask
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////test11.db'

models.py

from flask.ext.sqlalchemy import SQLAlchemy
from app import app
db = SQLAlchemy(app)

class User(db.Model):
    __tablename__ = 'users'
    uid = db.Column(db.Integer, primary_key = True)
    firstname = db.Column(db.String(100))
    lastname = db.Column(db.String(100))
    email = db.Column(db.String(120), unique=True)
    pwdhash = db.Column(db.String(54))

    def __init__(self, firstname, lastname, email, password):
        self.firstname = firstname.title()
        self.lastname = lastname.title()
        self.email = email.lower()
        self.set_password(password)

    def set_password(self, password):
        self.pwdhash = (password)

    def check_password(self, password):
        return password

routes.py

from models import User, db

db.create_all()
db.session.commit()

admin = User('admin', '[email protected]', 'admin1', '[email protected]')
guest = User('admi2', '[email protected]', 'admin', '[email protected]')
db.session.add(admin)
db.session.add(guest)
db.session.commit()

I'd definitely suggest looking over some tutorials! You'll need it: you should learn about web vulnerabilities, best practices, and so on.

Answered By - Ryan O'Donnell