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.

: Keywords should be in UPPERCASE (e.g., SELECT , FROM , WHERE ) to distinguish them from table and column names, which should follow a consistent snake_case or PascalCase naming convention.

: 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 . wynajem.sql

: 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

: Use descriptive aliases for tables (e.g., FROM Wynajmy AS w ) instead of single letters to improve clarity in multi-table joins. 3. Performance & Optimization : Ensure foreign keys (e

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

: Add inline comments ( -- ) or block comments ( /* ... */ ) to explain complex logic, such as how tax is calculated or how "available" status is determined. Ensure there is no redundant storage of rental

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