Flask-SQLAlchemy nullable = False

Question

I fiddled with Flask and the Flask-SQLAlchemy extension to create a simple registration form. In my User class, I have the "email" attribute equal to nullable = False, but when I test the form on the site without including email, it saves the new user in db instead of throwing an exception as I expected. Any idea why this is happening? Thanks for watching!

Here is 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 web form without entering email, it will contain an empty string "" .. not None ... and the empty string is not the same als null, and normally store it in a field.

I suggest using something like wtforms to validate user input.

Answer 2

You can add a solution if email != ''

Answer 3

you can use the html5 email attribute directly in html. See this .