@lanas
Yes to all of that, by all means read that overview link. I didn't say that "will be hard to retrive data from data base if i did not work with qtsql classes". Using the Python SQL classes instead would be fine for retrieving data from the database. But when you want to display that data in your Qt UI, rows & columns from your SQL queries, that will require some coding to get the Python-SQL-fetched-data to the Qt UI widgets and back. Whereas if you use the Qt classes they fill Qt models directly, and those are what Qt QTableViews use to display (and even edit) data.
In the simplest case, see if you can't use Qt's QSqlTableModel for attaching your data retrieval to the database. That will have the necessary SELECT/INSERT/UPDATE/DELETE automatically generated/issued for you for working on a SQL table in the database, without you having to write the SQL statements like you tried to in your question. And attaching a QTableView to the QSqlTableModel will display what you fetched without any code. And it can even allow you/the user to edit the data in the table and write ot back to the database for you.
