Model.create method not creating user

Question

I'm having some trouble creating a Flask app based off the work done in the Flask course. When I run my app, the database and table are created but the user isn't. I'm using PyCharm IDE like I have with all the other applications and the code checks out just fine with no errors.

models.py

import datetime

from flask.ext.bcrypt import generate_password_hash
from flask.ext.login import UserMixin
from peewee import *

DATABASE = SqliteDatabase('innovation.db')


class BaseModel(Model):
    class Meta:
        database = DATABASE


class User(UserMixin, BaseModel):
    username = CharField(unique=True)
    password = CharField(max_length=100)
    join_date = DateTimeField(datetime.datetime.now)
    is_admin = BooleanField(default=False)

    class Meta:
        order_by = ('username',)

    @classmethod
    def create_user(cls, username, password, admin=False):
        try:
            with DATABASE.transaction():
                cls.create(
                    username=username,
                    password=generate_password_hash(password),
                    is_admin=admin)
        except IntegrityError:
            raise ValueError("User already exists")


def initialize():
    DATABASE.connect()
    DATABASE.create_tables([User], safe=True)
    DATABASE.close()

app.py

from flask import Flask, g

import models


DEBUG = True
PORT = 5000
HOST = '0.0.0.0'

app = Flask(__name__)
app.secret_key = 'lkuas0df8708792134jkha)*&)*&LKHJSDF98734'


@app.before_request
def before_request():
    """Connect to the database before each request."""
    g.db = models.DATABASE
    g.db.connect()


@app.after_request
def after_request(response):
    """Connect to the database before each request and return response."""
    g.db.close()
    return response


@app.route('/')
def index():
    return 'Hello World!'


if __name__ == '__main__':
    models.initialize()
    try:
        models.User.create_user(
            username='testuser',
            password='password',
            admin=True
        )
    except ValueError:
        pass
    app.run(debug=DEBUG, host=HOST, port=PORT)

Answer 1 · 2015-11-20T19:56:48Z

November 20, 2015 7:56pm

You code is falling into the pit of misdirected exceptions: reraising the database IntegrityError as a ValueError when other issues are present.

Running your code interactively showed unusual behavior:

$ ipython3
Python 3.4.3 (default, Oct 14 2015, 20:28:29) 
Type "copyright", "credits" or "license" for more information.
IPython 1.2.1 -- An enhanced Interactive Python.

In [1]: import models

In [2]: models.initialize()

In [3]: models.User.create_user(username='testuser', password='password', admin=True)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-3-940256427ed0> in <module>()
----> 1 models.User.create_user(username='testuser', password='password', admin=True)

/home/chrisf/devel/Treehouse/questions/keith-doyle/models.py in create_user(cls, username, password, admin)
     40                     is_admin=admin)
     41         except IntegrityError:
---> 42             raise ValueError("User already exists")
     43 
     44 

ValueError: User already exists

In [4]: models.User.create_user(username='Beeblebrox', password='password', admin=True)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-4-cf0e6ac158c0> in <module>()
----> 1 models.User.create_user(username='Beeblebrox', password='password', admin=True)

/home/chrisf/devel/Treehouse/questions/keith-doyle/models.py in create_user(cls, username, password, admin)
     40                     is_admin=admin)
     41         except IntegrityError:
---> 42             raise ValueError("User already exists")
     43 
     44 

ValueError: User already exists

That's is weird, let's dig deeper. I comment out the try/except portion in User.create_user() and re-ran:

$ ipython3
Python 3.4.3 (default, Oct 14 2015, 20:28:29) 
Type "copyright", "credits" or "license" for more information.

IPython 1.2.1 -- An enhanced Interactive Python.
In [1]: import models

In [2]: models.User.create_user(username='Beeblebrox', password='password', admin=True)
---------------------------------------------------------------------------
IntegrityError                            Traceback (most recent call last)
<ipython-input-2-cf0e6ac158c0> in <module>()
----> 1 models.User.create_user(username='Beeblebrox', password='password', admin=True)

/home/chrisf/devel/Treehouse/questions/keith-doyle/models.py in create_user(cls, username, password, admin)
     38                     username=username,
     39                     password=generate_password_hash(password),
---> 40                     is_admin=admin)
     41         #except IntegrityError:
     42         #    raise ValueError("User already exists")

/home/chrisf/.virtualenvs/flasksocial/lib/python3.4/site-packages/peewee.py in create(cls, **query)
   4287     def create(cls, **query):
   4288         inst = cls(**query)
-> 4289         inst.save(force_insert=True)
   4290         inst._prepare_instance()
   4291         return inst

/home/chrisf/.virtualenvs/flasksocial/lib/python3.4/site-packages/peewee.py in save(self, force_insert, only)
   4459             rows = self.update(**field_dict).where(self._pk_expr()).execute()
   4460         else:
-> 4461             pk_from_cursor = self.insert(**field_dict).execute()
   4462             if pk_from_cursor is not None:
   4463                 pk_value = pk_from_cursor

/home/chrisf/.virtualenvs/flasksocial/lib/python3.4/site-packages/peewee.py in execute(self)
   3111             return self._qr
   3112         else:
-> 3113             cursor = self._execute()
   3114             if not self._is_multi_row_insert:
   3115                 if self.database.insert_returning:

/home/chrisf/.virtualenvs/flasksocial/lib/python3.4/site-packages/peewee.py in _execute(self)
   2533     def _execute(self):
   2534         sql, params = self.sql()
-> 2535         return self.database.execute_sql(sql, params, self.require_commit)
   2536 
   2537     def execute(self):

/home/chrisf/.virtualenvs/flasksocial/lib/python3.4/site-packages/peewee.py in execute_sql(self, sql, params, require_commit)
   3337             else:
   3338                 if require_commit and self.get_autocommit():
-> 3339                     self.commit()
   3340         return cursor
   3341 

/home/chrisf/.virtualenvs/flasksocial/lib/python3.4/site-packages/peewee.py in __exit__(self, exc_type, exc_value, traceback)
   3183             else:
   3184                 exc_args = exc_value.args
-> 3185             reraise(new_type, new_type(*exc_args), traceback)
   3186 
   3187 class _BaseConnectionLocal(object):

/home/chrisf/.virtualenvs/flasksocial/lib/python3.4/site-packages/peewee.py in reraise(tp, value, tb)
    121     def reraise(tp, value, tb=None):
    122         if value.__traceback__ is not tb:
--> 123             raise value.with_traceback(tb)
    124         raise value
    125 elif PY2:

/home/chrisf/.virtualenvs/flasksocial/lib/python3.4/site-packages/peewee.py in execute_sql(self, sql, params, require_commit)
   3329             cursor = self.get_cursor()
   3330             try:
-> 3331                 cursor.execute(sql, params or ())
   3332             except Exception as exc:
   3333                 if self.get_autocommit() and self.autorollback:

IntegrityError: NOT NULL constraint failed: user.join_date

Now it is clear: There is an issue with the user.join_date field.

It looks like you left off the "default=" in the User field definition:

    joined_at = DateTimeField(default=datetime.datetime.now)

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Keith Doyle

Keith Doyle

Model.create method not creating user

models.py

app.py

1 Answer

Chris Freeman

Chris Freeman

Keith Doyle

Keith Doyle