Wynajem.sql -

: Replace SELECT * with explicit column names. This reduces unnecessary data transfer and prevents issues if the table schema changes .

: Use CREATE TABLE IF NOT EXISTS or DROP TABLE IF EXISTS to ensure the script can be run multiple times without errors. wynajem.sql

: Verify that the rental data is normalized (e.g., separate tables for Klienci (Customers), Obiekty (Properties/Items), and Wynajmy (Rentals)). Ensure there is no redundant storage of rental rates in the transaction table if they can be retrieved via a JOIN from the primary item table . : Replace SELECT * with explicit column names