unresolved attribute "Column" in class "SQLAlchemy" - python

i use pycharm 5.0 and python3.5.And i download all the liarbry by the build-in function of pycharm(setting-project-project interpreter-"+").other libraries appear well,but some problems happens to flask-SQLAlchemy.
i import flask-SQLAlchemy successfully.however,pycharm remind me that "unresolved attribute reference 'Column' in class'SQLAlchemy'"."unresolved attribute reference 'relationship' in class 'SQLAlchemy'" and so on.
I have try some ways ,but they didn't work.for example:1.restart 2.remove and redownload 3.refresh the cache.which mention in PyCharm shows unresolved references error for valid code
code:
from flask import Flask, redirect, render_template, session, url_for, flash
from flask_sqlalchemy import SQLAlchemy
from flask_bootstrap import Bootstrap
from flask_wtf import Form
from wtforms import StringField, SubmitField
import os
from wtforms.validators import data_required
basedir = os.path.abspath(os.path.dirname(__file__))
app = Flask(__name__)
app.config['SECRET_KEY'] = 'hard to guess string'
app.config['SQLALCHEMY_DATABASE_URI'] =\
'sqlite:///' + os.path.join(basedir, 'data.sqlite')
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
bootstrap = Bootstrap(app)
db = SQLAlchemy(app)
class Role(db.Model):
__tablename__ = 'roles'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(64), unique=True)
users = db.relationship('User', backref='role', lazy='dynamic')
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.Integer, db.ForeignKey('roles.id'))
def __repr__(self):
return '<User %r>' % self.username
how can i solve this problem?

The constructor of the flask_sqlalchemy.SQLAlchemy class calls _include_sqlalchemy, which attaches all attributes from sqlalchemy and sqlalchemy.orm to its instances.
This is only done at runtime and not detected by PyCharm's code inspection.
It would require flask_sqlalchemy to use a more standard way of importing those attributes, like from sqlalchemy import *. But this would import the attributes into the flask_sqlalchemy module instead of each instance of SQLAlchemy and thus change the way they're accessed.
I'm not a Python or SQLAlchemy expert and won't judge whether this is good design or not but you could open an issue on https://github.com/pallets/flask-sqlalchemy and discuss it there.

here is what I do.
from flask_sqlalchemy import SQLAlchemy
from typing import Callable
class MySQLAlchemy(SQLAlchemy): # Or you can add the below code on the SQLAlchemy directly if you think to modify the package code is acceptable.
Column: Callable # Use the typing to tell the IDE what the type is.
String: Callable
Integer: Callable
db = MySQLAlchemy(app)
class User(db.Model, UserMixin):
__tablename__ = "users"
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(20)) # The message will not show: Unresolved attribute reference 'Column' for class 'SQLAlchemy'
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def create_test_data():
db.create_all()
test_user = User(name='Frank') # I add __init__, so it will not show you ``Unexpected argument``
db.session.add(test_user)
db.session.commit()

I've ran into the same problem just now.
In short if I just hit Run the code runs with exit code 0 even is PyCharm shows Unresolved attribute reference
but for anyone who might make the same mistake as I did before simply hitting Run:
This is the code that I was writing and it showed 'Unresolved attribute reference 'Column' for class 'SQLAlchemy'' also for eg. 'Unresolved attribute reference 'Integer' for class 'SQLAlchemy' '.
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///new-books-collection.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] =
False
db = SQLAlchemy(app)
class Books(db.Model):
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String(250), unique=True, nullable=False)
author = db.Column(db.String(250), unique=True, nullable=False)
rating = db.Column(db.Float, nullable=False)
db.create_all()
My problem was that I hovered over Column and Integer and clicked Add method Column() to class SQLAlchemy. Also the same with Integer.
From that moment TypeErrors came up for me because it created these empty methods in __init__.py of SQLAlchemy.
To solve this I used pip install flask_sqlalchemy --upgrade and pip install flask_sqlalchemy. And did not Add methods again. It still showed Unresolved attribute reference, but the code ran with exit code 0 and the database was created, with the right data inside.
Hope that helps!

Check the version of flask_sqlalchemy in your pycharm or environment.
i had same problem ,the easiest solution
pip install flask_sqlalchemy --upgrade
100% its gone work.

Related

Flask-SQLAlchemy Attribute Error 'SignallingSession' object has no attribute 'main'

I'm currently trying my hand at Flask-SQLAlchemy and I'm running into the following problem when it comes to running the commit() method:
First, here is my User class:
from flask_login import LoginManager, UserMixin
from flask_sqlalchemy import Model, SQLAlchemy
from app import db
class User(db.Model, UserMixin):
def __init__(self, id, name, password, active):
self.id = id
self.name = name
self.password = password
self.active = active
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String, nullable=False, unique=True)
password = db.Column(db.String, nullable=False)
active = db.Column(db.Boolean, nullable=False, default=True)
#property
def is_active(self):
return self.active
Now my main app:
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///database.sqlite'
app.secret_key = b'test'
db = SQLAlchemy(app)
from user import User
db.create_all()
db.session.commit() # This commit works fine!
admin = User(1, 'admin', 'admin', True)
db.session.add(admin)
db.session.commit() # <------ Value Error at this position
print(User.query.all())
And I get the following Error message when I try to run my code:
in flask_sqlalchemy\__init__.py
before_models_committed.send(session.main, changes=list(d.values()))
AttributeError: 'SignallingSession' object has no attribute 'main'
I am using Pycharm and the version of flask_sqlalchemy is 2.5.1
Am I using the module wrong?
Thank you for every helpfull comment!
Kind regards,
Bagheera
Now I don't know if this really counts as a solution, but I tried lowering the version of the flask_sqlalchemy module.
After this didn't work either, because now other error messages appeared, I set the version back to the highest.
After that it worked in a mysterious way. But maybe someone has an explanation for this or experienced something similar.

getting "User" is not accessedPylance - error notification

I have installed python 3.9.7 64-bit in Windows 10 - I am using VSCode editor- installed flask, flask-login, flask-sqlalchemy using pip install command line. I created models.py with below commands
from .import db
from flask_login import UserMixin
from sqlalchemy.sql import func
# Defined Class note#
class Note(db.Model):
id = db.Column(db.Integer, primary_key=True)
data = db.Column(db.String(10000))
date = db.Column(db.DateTime(timezone=True), default=func.now())
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
#defined class User#
class User(db.Model, UserMixin):
id = db.Column(db.Integer, primary_key=True)
email = db.Column(db.String(150), unique=True)
password = db.Column(db.String(150))
first_name = db.Column(db.String(150))
notes = db.relationship('Note')
Then created Python file init.py to get the data values. but due to the pylance notification, unable to create the database.db file after running the below command.
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from os import path
db = SQLAlchemy()
DB_NAME = "database.db"
def create_app():
app = Flask(__name__)
app.config['SECRET_KEY'] = 'gjkagfkag khsgfafhl'
app.config['SQLQLCHEMY_DATABASE_URI'] = f'sqlite:///{DB_NAME}'
db.init_app(app)
from.views import views
from.auth import auth
app.register_blueprint(views, url_prefix='/')
app.register_blueprint(auth, url_prefix='/')
from.models import User,Note (**# this line is Getting notification highlighter** -(class)user and (class) Note is not accessed Pylance)
create_database(app)
return app
def create_database(app):
if not path.exists('website/' + DB_NAME):
db.create_all(app = app)
print('Created Database!')
Screen shot:
Notification from pylance
There is absolutely no problem with this message. In fact, is not an Error message, it's more like a Info message.
Pylance is telling you that you have imported the User class, but you're not using it. Therefore, User is not accessed. If you hover your cursor over the Note import, the same message will appear and for all variables and imports that you are not using it.
Bonus: Your app config is wrong at the "SQLQLCHEMY_DATABASE_URI". I believe that is "SQLALCHEMY_DATABASE_URI".

Need Help: AttributeError: "SQLAlchemy" object has no attribute 'Models'

AttributeError: sqlalchemy object has no attribute "Models" error is occurring. I already installed all requirements like pip install sqlalchemy, flask-sqlalchemy, psycopy2-binary. this file name is create.py
import os
from flask import Flask, render_template, request
from models import *
app = Flask(__name__)
app.config["SQLALchemy_DATABASE_URI"] = os.getenv("DATABASE_URL")
app.config["SQLALchemy_TRACK_MODIFICATIONS"] = False
db.init_app(app)
def main():
db.create_all()
if __name__ == "__main__":
with app.app_context():
main()
this file is models.py
from flask_sqlalchemy import SQLAlchemy
db=SQLAlchemy()
class Flight(db.Models):
__tablename__ = "flights"
id = db.Column(db.Integer, primary_key=True)
origin = db.Column(db.String, nullable=False)
destination = db.Column(db.String, nullable=False)
duration = db.Column(db.Integer, nullable=False)
class Passenger(db.Models):
__tablename__ = "passengers"
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String, nullable=False)
flight_id = db.Column(db.Integer, db.ForeignKey("flights.id",
nullable=False))
output is:
Traceback (most recent call last):
File "create.py", line 4, in
from models import *
File "D:\web\flaskrun\models.py", line 5, in
class Flight(db.Models):
AttributeError: 'SQLAlchemy' object has no attribute 'Models'
As mentioned in the flask-sqlalchemy docs your models need to derive from db.Model without the trailing s
Furthermore it provides a class called Model that is a declarative base which can be used to declare models:
It should be db.Model instead of db.Models.
I got this same error because there was typing mistake I made the s small in string method for datatype like
db.String()--->correct
db.string()--->Incorrect
name=db.Column(db.String(),nullable=False)
Hope this helps someone

Flask-SQLAlchemy's create_all does not create tables

I'm working on a flask application where I'm trying to isolate my unit tests. I'm using flask-sqlalchemy, and I'm trying to use the create_all and drop_all methods to clean my database after running a test.
However, it appears my create_all and drop_all methods do not actually create/drop the tables as the documentation states. I have my models imported in the application before calling create_all, like most other answers say.
This is the error I'm getting with the code below:
psycopg2.ProgrammingError: relation "tasks" does not exist
Here's my relevant code
/app.py
import os
import configparser
from flask import Flask
from src.router import router
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
app = Flask(__name__)
if not os.path.exists(os.path.join(app.root_path, 'config.ini')):
raise Exception(f'config.ini not found in the {app.root_path}')
config = configparser.ConfigParser()
config.read('config.ini')
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = config[os.environ['APP_ENV']]['DATABASE_URI']
app.register_blueprint(router)
db = SQLAlchemy(app)
migrate = Migrate(app, db)
if __name__ == "__main__":
app.run()
/tests/test_router.py
from unittest import TestCase
from flask import Flask
from app import app, db
from src.models import Task
class TestRouter(TestCase):
def setUp(self):
db.create_all()
def tearDown(self):
db.drop_all()
def test_adds_task(self):
task = Task(task_id='task_1', name='my task')
db.session.add(task)
db.session.commit()
I think I was a little quick to post the question, but I hope this might help others come up with other ideas on how to troubleshoot a similar issue.
In my src/models.py file where I keep my models, you must make sure that your models are defined correctly. Since Flask-SQLAlchemy is a wrapper around the SQLAlchemy you must use the data types under the db object.
Essentially, I had my models defined as such:
class Task(db.Model):
__tablename__ = 'tasks'
id = Column(Integer, primary_key=True)
task_id = Column(String)
name = Column(String)
created_at = Column(DateTime, default=datetime.datetime.now)
As you can see, I was inheriting from db.Model instead of the return value of declarative_base(). I also needed to add the db. in front of all the data types, including Column, Integer, String, Float, DateTime, relationship, and ForeignKey.
So, I was able to fix my issue by changing my model to something like:
class Task(db.Model):
__tablename__ = 'tasks'
id = db.Column(db.Integer, primary_key=True)
task_id = db.Column(db.String)
name = db.Column(db.String)
created_at = db.Column(db.DateTime, default=datetime.datetime.now)
See: Documentation on declaring Flask-SQLAlchemy models

AttributeError: 'BaseQuery' object has no attribute 'whoosh_search'

I am using Flask (python), creating whooshe search, I have followed all steps from this link, also tried from other links too, but every time at end I came to this error:
results = BlogPost.query.whoosh_search('cool')
AttributeError:'BaseQuery' object has no attribute 'whoosh_search'
Here is my model code:
class BlogPost(db.Model):
__tablename__ = 'blogpost'
__searchable__ = ['title', 'content']
__analyzer__ = StemmingAnalyzer()
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.Unicode) # Indexed fields are either String,
content = db.Column(db.Text) # Unicode, or Text
created = db.Column(db.DateTime, default=datetime.utcnow)
I am having error on this:
#app.route('/search')
def search():
results = BlogPost.query.whoosh_search('cool')
return results
I have also seen this error.Then I found the error is in models.py.You should add the whooshalchemy.whoosh_index(app, BlogPost) at the end of the model code.
I ran in to a similar issue if anyone falls down thsi rabbit hole.
In my case, i found that in my models.py i was importing from sqlalchemy and using the declarative_base as a base for each model.
ie:
from sqlalchemy import Column, Integer, DateTime, Text, Boolean
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Book(Base):
while in my routes.py I was importing flask-sqlalchemy where you use db.Model as the base:
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
db.init_app(app)
class Book(db.Model):
There have been some similar answers on some other posts as well but it looks like when using flask-whooshalchemy or its similar variants (whooshalchemy3, whooshalchemyplus) using db.Model as the base is the correct way to init the model to have the appropriate attributes.
hopefully that helps someone down the road.

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