Connecting to Sqlalchemy database with PyQt and saving database contents into a TableView in PyQt

Question

I am currently working on an application that can access an sqlalchemy database using PyQt and displaying its contents into a TableView or some other widget. To keep it simple for now, lets just say that is a phonebook with a name, number, and street address. I would like to have the Tableview periodically update itself so if something is added to the database, it will refresh itself. connection to the database will also be done wirelessly, so I won't know if a change has been made. I have written some code that I modified from a postgrese database. But I have found poor documentation for the sqlalchemy aspect as well as for connecting with a engine driver in PyQt. Any help is appreciated or even a clear example. Thank you in advance.

engine = create_engine('postgresql+psycopg2://postgres::[email protected]:5432/masterdb') 

The code above is just for creating the engine to connect to the sqlalchemy database

Answer 1

What you are asking is basically a millisecond refresh of the GUI contents which could be very straining on the server if the size of the data is huge and or if no of people accessing it is a lot. I would instead add a "refresh" push button that reloads the data from the database and puts it on to the qtablewidget when its clicked.

For connect through sqlalchemy to postgresql, I use this:

import sqlalchemy
User = "xxxx"
Pass = "xxxx"
Host = "192.168.x.x"
Port = "xxxx"
DB = "xxxx"
SQLEngine =   sqlalchemy.create_engine('postgresql://'+User+':'+Pass+'@'+Host+':'+Port+'/' + DB,poolclass=sqlalchemy.pool.NullPool)

I use pandas to read the data from postgresql:

import pandas as pd
Data = pd.read_sql_query('select * from tablename ', con=SQLEngine)