Connecting to a PostgreSql table with flask-sqlalchemy returns no records

Question

I'm new to SQLAlchemy and PostgreSql, so apologies for the newbie question. I'm trying to connect to a table in a remote PostgreSql server using flask-alchemy, and read all the table records. It doesn't have to be flask-sqlalchemy specifically, but I do need to read the table records.

The table has 3 records, but it always comes back as zero records when I step through the code.

I'm using python 3.7, visual studio code with an virtual environment in windows 10.

I checked several articles already:

https://flask-sqlalchemy.palletsprojects.com/en/2.x/#

https://stackabuse.com/using-sqlalchemy-with-flask-and-postgresql/

https://realpython.com/flask-by-example-part-2-postgres-sqlalchemy-and-alembic/

https://www.askpython.com/python-modules/flask/flask-postgresql

Here's my app.py code:

import sys, os
from flask import Flask, request, jsonify, make_response, session

# SQL ALCHEMY imports
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://userid:password@server:1234/db_name'
db = SQLAlchemy(app)
migrate = Migrate(app, db)

class DummyTable(db.Model):
    field_id = db.Column(db.Integer, primary_key=True)
    desc = db.Column(db.String(10), nullable=False)

    def __repr__(self):
        return '<Desc %r>' % self.desc

@app.route('/test', methods=["GET"])
def get_records():
    from app import DummyTable
    
    db.create_all()
    dummy_table = DummyTable.query.all()

    results = [
            {
                "field_id": dummy_table.field_id,
                "desc": dummy_table.desc
            } for record in dummy_table]

    return {"results": results}

if __name__ == "__main__":
    app.run()

Any help is really appreciated. Thanks.

Answer 1

I believe you're missing a

db.session.commit()

After db.create_all()

Answer 2

I ended up using psycopg2 instead

import psycopg2

conn = psycopg2.connect(dbname="blah", user="blah", password="blah", host="some-machine", port="9999")

cur = conn.cursor()
cur.execute("SELECT * FROM private_schema.mytable;")

items = cur.fetchall()

for row in items:
    print("pkey = ", row[0], )
    print("val = ", row[1], "\n")

cur.close()
conn.close()