: Use explicit INNER JOIN or LEFT JOIN syntax rather than comma-separated tables in the WHERE clause for better readability and maintenance . 4. Safety & Transactions
: For operations involving multiple updates (e.g., marking an item as "rented" while creating a billing record), wrap the logic in a BEGIN TRANSACTION and COMMIT to maintain data integrity. wynajem.sql
: Ensure foreign keys (e.g., klient_id , obiekt_id ) and frequently filtered columns (like data_wynajmu ) are properly indexed to speed up search queries. : Use explicit INNER JOIN or LEFT JOIN
: 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 . : Ensure foreign keys (e