Flask-SQLAlchemy nullable=False

Question

I'm messing around with Flask and the Flask-SQLAlchemy extension to create a simple registration form. In my User class, I have the attribute "email" set to nullable=False, but when I test the form on the site without including an email, it saves the new user to the db instead of throwing an exception as I expected. Any idea why that's happening? Thanks for looking!

Here's the code:

from flask import Flask, url_for, render_template, request, redirect
from flaskext.sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////tmp/kloubi.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(80), unique=True, nullable=False)
    fname = db.Column(db.String(80))
    lname = db.Column(db.String(80))

    def __init__(self, username, email, fname, lname):
        self.username = username
        self.email = email
        self.fname = fname
        self.lname = lname

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/register/', methods=['GET', 'POST'])
def register():
    if request.method == 'POST':
        new_user = User(fname = request.form['name'], 
                        lname = request.form['surname'],
                        email = request.form['email'],
                        username = request.form['username'])
        db.session.add(new_user)
        db.session.commit()
        return redirect(url_for('index'))
    return render_template('register.html')

if __name__ == '__main__':
    app.debug = True
    app.run(host='0.0.0.0')

Answer 1

The problem is when you submit the webform without entering an email it will contain an empty string "" .. not None... and an empty string is not the same als null and it is ok to store it in the field.

I suggest using something like wtforms to validate the input of the user.