SQLALchemy .query: Unresolved attribute reference 'query' for class 'Car'

Question

I have an issue that was already mentioned here https://youtrack.jetbrains.com/issue/PY-44557

But I couldn't find a solution yet. I'm using Python Flask with SQLAlchemy to create an API service.

Here are my imports:

from flask import Flask, jsonify, request
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import Column, Integer, String, Float
import os
from flask_marshmallow import Marshmallow


app = Flask(__name__)
basedir = os.path.abspath(os.path.dirname(__file__))
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///'+os.path.join(basedir, 'dealers.db')


db = SQLAlchemy(app)
ma = Marshmallow(app)

Here is my data model:

class Car(db.Model):
    __tablename__ = 'cars'
    car_id = Column(Integer, primary_key=True)
    car_name = Column(String)
    car_type = Column(String)
 

class CarSchema(ma.Schema):
    class Meta:
        fields = ('car_id', 'car_name', 'car_type')

car_schema = CarSchema()  
cars_schema = CarSchema(many=True)

I'm having an issue/Warning with my UDF when I use .query

def cars():
    car_list = Car.query.all()  # *Unresolved attribute reference 'query' for class 'Car'
    result = cars_schema.dump(car_list)
    return jsonify(result)

This appears to be a bug in JetBrains. You can see the information here: https://youtrack.jetbrains.com/issue/PY-44557 — CodeLikeBeaker, Dec 30 '20 at 20:58

chaos · Accepted Answer · 2021-04-08T15:01:22.470

I've found out how to make a hacky and partial solution for this issue using type-hinting stubs.

Create abstract python class derived from db.Model in a separate file and a "stub"-file with a same name

Example:

abstract.py:

class AbstractBaseModel(db.Model):
    __abstract__ = True

abstract.pyi:

from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import orm
from sqlalchemy.ext.declarative import DeclarativeMeta


db: SQLAlchemy = SQLAlchemy()


class _FBase(db.Model):
    query: orm.Query


class AbstractBaseModel(_FBase, DeclarativeMeta):
    ...

Then make models deriving from abstract.AbstractBaseModel instead of db.Model e.g:

from abstract import AbstractBaseModel

class Car(AbstractBaseModel):
    __tablename__ = 'cars'
    car_id = Column(Integer, primary_key=True)
    car_name = Column(String)
    car_type = Column(String)

I've also created a sample project for testing this workaround

score 0 · Answer 2 · answered Jan 01 '21 at 15:33

Modify class Car(db.Model): to be:

class Car(db.Model):
    __tablename__ = 'cars'
    car_id = db.Column(db.Integer, primary_key=True)
    car_name = db.Column(db.String) # it is better to give string length for example db.String(100)
    car_type = db.Column(db.String)

where you should define Columns to be related to db

SQLALchemy .query: Unresolved attribute reference 'query' for class 'Car'

2 Answers2

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