I defined table name users_table and run db.create_all() to create the table, but get error "no such table user_table" on commit for updating user info.
How I test :
(under /project) python3 manage.py shell
>>> u = User(email='foo#bar.com', username='foobar', password='player')
>>> db.create_all()
>>> db.session.add(u)
>>> db.session.commit() # with following error message
Traceback (most recent call last):
File "C:\...\Python\Python36-32\lib\site-packages\sqlalchemy\engine\base.py", line 1182, in _execute_context
context)
File "C:\...\Python\Python36-32\lib\site-packages\sqlalchemy\engine\default.py", line 470, in do_execute
cursor.execute(statement, parameters)
sqlite3.OperationalError: no such table: users_table
...
...
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such table: users_table
/project/app/_init_.py:
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from config import config
db = SQLAlchemy()
def create_app(config_name):
app = Flask(__name__)
app.config.from_object(config[config_name])
config[config_name].init_app(app)
db.init_app(app)
return app
/project/app/models.py:
import os
from flask_sqlalchemy import SQLAlchemy
from werkzeug.security import generate_password_hash
from flask import Flask
basedir = os.path.abspath(os.path.dirname(__file__))
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'data.sqlite')
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
db = SQLAlchemy(app)
class User(db.Model):
__tablename__ = 'users_table'
id = db.Column(db.Integer, primary_key=True)
email = db.Column(db.String(64), unique=True, index=True)
username = db.Column(db.String(64), unique=True, index=True)
password_hash = db.Column(db.String(128))
def __repr__(self):
return '<User %r>' % self.username
#property
def password(self):
raise AttributeError('Password is not a readable attribute')
#password.setter
def password(self, password):
self.password_hash = generate_password_hash(password)
project/config.py:
import os
basedir = os.path.abspath(os.path.dirname(\__file__))
class Config:
SECRET_KEY = os.environ.get('SECRET_KEY') or 'fhuaioe7832of67^&*T#oy93'
SQLALCHEMY_COMMIT_ON_TEARDOWN = True
#staticmethod
def init_app(app):
pass
class DevelopmentConfig(Config):
DEBUG = True
SQLALCHEMY_DATABASE_URI = 'sqlite:///' + os.path.join(basedir, 'data.sqlite')
config = {
'development': DevelopmentConfig,
'default': DevelopmentConfig,
}
project/manage.py:
import os
from app import create_app, db
from app.models import User
from flask_script import Manager, Shell
app = create_app(os.getenv('FLASK_CONFIG') or 'default')
manager = Manager(app)
def make_shell_context():
return dict(app=app, db=db, User=User)
manager.add_command("shell", Shell(make_context=make_shell_context))
if __name__ == '__main__':
manager.run()
I just got done setting up a Flask app and I dealt with this kind of problem.
I strongly suspect the problem here is that the instance of db that you are creating in __init__.py is unaware of the contents of models.py, including the User class. The db object in __init__.py is a totally separate object from the db you are creating in models.py. So when you run db.create_all() in __init__.py, it is checking the list of tables that it knows about and isn't finding any. I ran into this exact issue.
What I discovered is that the models (like User) are registered with the particular db object that is listed in the model's class definition (e.g. class User(db.Model):).
So basically my understanding is that the way to fix this is to run db.create_all() using the same instance of db that is being used to define the models. In other words, run db.create_all() from within models.py.
Here's my code so you can see how I have it set up:
app.py:
#!flask/bin/python
import os
from flask import Flask
class CustomFlask(Flask):
jinja_options = Flask.jinja_options.copy()
jinja_options.update(dict(
variable_start_string='%%', # Default is '{{', I'm changing this because Vue.js uses '{{' / '}}'
variable_end_string='%%',
))
app = CustomFlask(__name__)
app.config['SECRET_KEY'] = 'hard to guess string'
import yaml
if os.environ['SERVER_ENVIRONMENT'] == 'PRODUCTION':
config_filename = "production.yaml"
elif os.environ['SERVER_ENVIRONMENT'] == 'LOCAL':
config_filename = "local.yaml"
else:
config_filename = "local.yaml"
base_directory = path = os.path.dirname(os.path.realpath(__file__))
with open(base_directory + "/config/" + config_filename) as config_file:
config = yaml.load(config_file)
db_config = config['database']
SQLALCHEMY_DATABASE_URI = "mysql+mysqlconnector://{username}:{password}#{hostname}/{databasename}".format(
username=db_config['username'],
password=db_config['password'],
hostname=db_config['hostname'],
databasename=db_config['databasename'],
)
app.config["SQLALCHEMY_DATABASE_URI"] = SQLALCHEMY_DATABASE_URI
app.config["SQLALCHEMY_POOL_RECYCLE"] = 299
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy(app)
db.app = app
def clear_the_template_cache():
app.jinja_env.cache = {}
app.before_request(clear_the_template_cache)
from flask_login import LoginManager
login_manager = LoginManager()
login_manager.init_app(app)
#login_manager.user_loader
def load_user(email):
from models import User
return User.query.filter_by(email=email).first()
if __name__ == '__main__':
from routes import web_routes
app.register_blueprint(web_routes)
from api import api
app.register_blueprint(api)
# To get PyCharm's debugger to work, you need to have "debug=False, threaded=True"
#app.run(debug=False, threaded=True)
app.run(debug=True)
models.py:
from app import db
import datetime
from werkzeug.security import generate_password_hash, \
check_password_hash
class Song(db.Model):
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
name = db.Column(db.String(80))
datetime_created = db.Column(db.DateTime, default=datetime.datetime.utcnow())
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
lines = db.relationship('Line', cascade="all,delete", backref=db.backref('song', lazy='joined'), lazy='dynamic')
is_deleted = db.Column(db.Boolean, default=False)
class Line(db.Model):
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
song_id = db.Column(db.Integer, db.ForeignKey('song.id'))
spans_of_time = db.relationship('SpanOfTime', cascade="all,delete", backref=db.backref('line', lazy='joined'), lazy='dynamic')
class SpanOfTime(db.Model):
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
line_id = db.Column(db.Integer, db.ForeignKey('line.id'))
starting_64th = db.Column(db.Integer) # I'm assuming the highest-granularity desired will be a 1/64th note-length.
length = db.Column(db.Integer) # I guess this'll be in 1/64th notes, so a 1/16th note will be '4'.
content = db.Column(db.String(80))
class User(db.Model):
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
email = db.Column(db.String(80), primary_key=True, unique=True)
display_name = db.Column(db.String(80), default="A Rhymecraft User")
password_hash = db.Column(db.String(200))
datetime_subscription_valid_until = db.Column(db.DateTime, default=datetime.datetime.utcnow() - datetime.timedelta(days=1))
datetime_joined = db.Column(db.DateTime, default=datetime.datetime.utcnow())
songs = db.relationship('Song', cascade="all,delete", backref=db.backref('user', lazy='joined'), lazy='dynamic')
def __init__(self, email, password):
self.email = email
self.set_password(password)
def __repr__(self):
return '<User %r>' % self.email
def set_password(self, password):
self.password_hash = generate_password_hash(password)
def check_password(self, password):
return check_password_hash(self.password_hash, password)
def is_authenticated(self):
return True
def is_active(self):
return True
def is_anonymous(self):
return False
def get_id(self):
return str(self.email)
def init_db():
db.create_all()
# Create a test user
new_user = User('a#a.com', 'aaaaaaaa')
new_user.display_name = 'Nathan'
db.session.add(new_user)
db.session.commit()
new_user.datetime_subscription_valid_until = datetime.datetime(2019, 1, 1)
db.session.commit()
if __name__ == '__main__':
init_db()
Very simple solution: in the app.py or main.py you can just add these lines of code for fixing this issue:
#app.before_first_request
def create_tables():
db.create_all()
In your case, require to add following code into __init__.py:
from models import User, Role
#app.shell_context_processor
def make_shell_context():
return dict(db=db, User=User, Role=Role)
then you do your previous works, it's all work.
I run into the same problem, after doing a YT tutorial. I solved it by adding this code at the end of my __init__.py
from .models import User, Post
with app.app_context():
db.create_all()
Sidenote: Most tutorials don't use the with app.app_context(): . I think there was a update in flask, which is why this is needed. This caused errors in my code and maybe it helps someone who reads this.
I would like to mention that it was the flask tutorial from "corey schafer" after "part 6 - user authentication", and the error appeared when i ran some tests. just in case anyone else is doing the exact same tutorial and therfore finds it easier to identify my answer as helpful. I am not mentioning the creater for advertisement. I hope this is ok.
Create a folder named "instance" in the root directory and move your database file to that folder.
Related
I have been trying to solve an issue related to SQLALCHEMY in Flask as my db is not getting created even though I set the SQLACHEMY_DATABASE_URI to "app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///test.db'".
In the warning it says the 'sqlite:///:memory:'. When db.create_all() is call test.sql file is not created and also in the UI I see errors as mentioned bellow:
Instance of 'SQLAlchemy' has no 'Column' memberpylint(no-member) and 3 others
Please help in resolving this issue and generating the db and SQL file.
from flask import Flask, render_template, url_for
from flask_sqlalchemy import SQLAlchemy
from datetime import datetime
#Initializing database
app = Flask(__name__)
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///test.db'
db = SQLAlchemy(app)
#Creating model
class Todo(db.Model):
id = db.Column(db.Integer, primary_key=True)
content = db.Column(db.String(200), nullable=False)
completed = db.Column(db.Integer, default=0)
date_created = db.Column(db.DateTime, default=datetime.utcnow)
def __repr__(self):
return '<Task %r>' % self.id
app = Flask(__name__)
#app.route('/')
def index():
return render_template('index.html')
if __name__ == "__main__":
app.run(debug=True)
First of all, I have tried looking for answers in this website. But no luck...
What I wanna achieve is that starting an independent thread in the request handling thread to do some asynchronous task. The tricky point is that there are some database operations needed in this independent thread.
Here is an example. Five files included.
project
|__manager.py
|__config.py
|__deployer
|__`__init__.py`
|__models.py
|__views.py
|__operators.py
Detail code below...
# deployer/__init__.py
from flask import Flask
from deployer.models import db
def create_app():
app = Flask(__name__)
app.config.from_object(object_name)
db.init_app(app)
# Add route for index
#app.route('/')
def index():
return {'code': 200, 'message': 'OK'}
return app
# manager.py
from os import environ
from flask_script import Manager, Server
from deployer import create_app
from flask_restful import Api
from deployer.views import HostView
env = environ.get('APM_ENV', 'dev')
app = create_app('config.%sConfig' % env.capitalize())
api = Api(app)
api.add_resource(HostView, '/api/v1/hosts')
manager = Manager(app)
manager.add_command("server", Server(host='0.0.0.0', port=9527))
if __name__ == '__main__':
manager.run(default_command='server')
# deployer/views.py
from flask_restful import Resource, reqparse
from flask import jsonify
from deployer.models import db, Host
from deployer.operators import HostInitiator
parser = reqparse.RequestParser()
parser.add_argument('host', type=int, help='Specify an unique host.')
class HostView(Resource):
def get(self):
h = db.session.query(Host).filter(Host.id == 1).one()
return jsonify(
host_id=h.id,
host_code=h.code,
host_ip=h.ip_addr_v4
)
def post(self):
h = Host(
code='Harbor',
ip_addr_v4='10.10.10.199',
state='created'
)
db.session.add(h)
db.session.commit()
initiator = HostInitiator(host=h)
initiator.start()
return {
'code': 'Harbor',
'ip_addr_v4': '10.10.10.199',
'state': 'created'
}
# deployer/models.py
from sqlalchemy import Column, Integer, String
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()
class Host(db.Model):
__tablename__ = 'br_host'
id = Column(Integer, primary_key=True, autoincrement=True)
code = Column(String(128), index=True, nullable=False)
ip_addr_v4 = Column(String(15), nullable=False)
state = Column(String(16), nullable=False)
# deployer/operators.py
from threading import Thread
from deployer.models import db
class HostInitiator(Thread):
def __init__(self, host):
super().__init__()
self.host = host
def run(self):
# Update Host.state [created-->initating]
db.session.query(Host).filter(Host.id == self.host.id).update({'state': 'initating'})
db.session.commit()
# do some initiating things...
# Update Host.state [initating-->ready]
db.session.query(Host).filter(Host.id == self.host.id).update({'state': 'ready'})
db.session.commit()
Always got outside application context error with code above. The error message indicates that no database operation is permitted in the HostInitiator thread.
It suggests me to push a context or move my code into a view function. I'm suffering this quite a while, please help out if you guys have any suggestions. Thanks in advance.
The code works for me
def test_multi_threading_query():
# module which i create Flask app instance
from app.main import app
# module which i create sqlalchemhy instance
from app.model.db import db, Post
with app.app_context():
posts = Post.query.all()
p = posts[0]
p.foo = 1
db.session.add(p)
db.session.commit()
print(p)
#api.route('/test')
def test_view():
from threading import Thread
t = Thread(target=test_multi_threading_query)
t.start()
return ''
# main.py
app = Flask(__main__)
#db.py
db = SQLAlchemy()
class Post(db.Model):
id = db.Column(db.Integer, primary_key=True)
foo = db.Column(db.Integer)
https://flask.palletsprojects.com/en/1.1.x/appcontext/
i was creating blog website using flask and flaskALacedemy and i got error please help me for this thank you
i was creating blog website using flask and flaskALacedemy and i got error please help me for this thank you
from flask import Flask,render_template,request
from flask_sqlalchemy import SQLAlchemy
from datetime import datetime
app=Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] =
'mysql://root:#localhost/myfirstweb'
db = SQLAlchemy(app)
class Contact(db.Model):
serial_no = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(20), unique=False, nullable=False)
email = db.Column(db.String(20), unique=False, nullable=False)
phone_no = db.Column(db.String(12), unique=False, nullable=False)
message = db.Column(db.String(120), unique=False, nullable=False)
date = db.Column(db.String(12), unique=False, nullable=True)
#app.route('/')
def home():
return render_template('index.html')
#app.route('/about')
def about():
return render_template('about.html')
#app.route('/contact', methods = ['GET', 'POST'])
def contact():
if(request.method=='POST'):
name = request.form.get('name')
email = request.form.get('email')
phone = request.form.get('phone')
message = request.form.get('message')
entry =
contact(name=name,email=email,phone_no=phone,date=datetime.now(),
message=message)
db.session.add(entry)
db.session.commit()
return render_template('contact.html')
#app.route('/post')
def post():
return render_template('post.html')
app.run(debug=True)
Your function contact doesn't expect any parameters and still you are still doing this: contact(name=name,email=email,phone_no=phone,date=datetime.now(), message=message)
I'm making migrations in Flask using unsurprisingly Flask-Migrate.
once I execute python manage.py db init it creates directory migrations with initial migrations file. Then
I execute python manage.py db migrate and I get this:
...
...
target_metadata = current_app.extensions['migrate'].db.metadata
AttributeError: 'NoneType' object has no attribute 'metadata'
I understand from this output that 'migrate' is None hence I'm getting an attribute error.
models.py:
from sqlalchemy.sql import func
from project import db, bcrypt
class User(db.Model):
__tablename__ = 'users'
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
username = db.Column(db.String(128), nullable=False, unique=True)
email = db.Column(db.String(128), nullable=False, unique=True)
password = db.Column(db.String(255), nullable=False)
active = db.Column(db.Boolean(), default=True, nullable=False)
created_date = db.Column(db.DateTime, default=func.now(), nullable=False)
def __init__(self, username, email, password):
self.username = username
self.email = email
self.password = bcrypt.generate_password_hash(password).decode()
def to_json(self):
return {
'id': self.id,
'username': self.username,
'email': self.email,
'active': self.active,
}
The question is why nothing is being passed to it ? I'm following a tutorial and I'm not supposed to have this error.
I've got this from similar topic:
NoneType means that instead of an instance of whatever Class or Object
you think you're working with, you've actually got None. That usually
means that an assignment or function call up above failed or returned
an unexpected result.
this is what I've found in env.py file in the migrations directory:
from flask import current_app
config.set_main_option('sqlalchemy.url',
current_app.config.get('SQLALCHEMY_DATABASE_URI'))
target_metadata = current_app.extensions['migrate'].db.metadata
current_app is being imported from Flask but doesn't contain the extension migrate from which I need to use the metadata.
There's no reason for it to be throwing None though because the extension is correctly initilised in __init__.py file:
...
...
from flask_migrate import Migrate
db = SQLAlchemy()
toolbar = DebugToolbarExtension()
cors = CORS()
migrate = Migrate()
bcrypt = Bcrypt()
def create_app(script_info=None):
app = Flask(__name__)
app_settings = os.getenv('APP_SETTINGS')
app.config.from_object(app_settings)
app.config.from_object('project.config.DevelopmentConfig')
toolbar.init_app(app)
cors.init_app(app)
db.init_app(app)
migrate.init_app(app) # <--
bcrypt.init_app(app)
from project.api.users import users_blueprint
app.register_blueprint(users_blueprint)
#app.shell_context_processor
def ctx():
return {'app': app, 'db': db}
return app
I had a missing argument in the initialization of the migrate extension. Migrate takes in the app instance and the instance of db.
def create_app(script_info=None):
app = Flask(__name__)
app_settings = os.getenv('APP_SETTINGS')
app.config.from_object(app_settings)
app.config.from_object('project.config.DevelopmentConfig')
toolbar.init_app(app)
cors.init_app(app)
db.init_app(app)
migrate.init_app(app, db) # <--
bcrypt.init_app(app)
from project.api.users import users_blueprint
app.register_blueprint(users_blueprint)
#app.shell_context_processor
def ctx():
return {'app': app, 'db': db}
return app
I'm just working my way through the book Flask Web Development. I'm stuck now and can't help myself.
This is the part of my code which makes the problem.
import os
from flask_script import Manager
from flask import Flask, render_template, session, redirect, url_for, flash
from flask_wtf import FlaskForm
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from wtforms import StringField, SubmitField, validators
from wtforms.validators import Required
from flask_sqlalchemy import SQLAlchemy
class NameForm(FlaskForm):
name = StringField('What is your name?', validators=[Required()])
submit = SubmitField('Submit')
class Role(db.Model):
__tablename__ = 'roles'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(64), unique=True)
users = db.Column('User',backref='role')
def __repr__(self):
return '<Role %r>' % self.name
class User(db.Model):
__tablename__ = 'users'
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(64), unique=True, index=True)
role_id = db.Column(db.Interger, db.ForeignKey('roles.id')
def __repr__(self):
return '<User %r>' % self.username
When I try to start the shell, I get the following error message:
line 30
def __repr__(self):
^
SyntaxError: invalid syntax
Guys where is the problem?
You are missing a closing brace ()) in this line:
role_id = db.Column(db.Interger, db.ForeignKey('roles.id')