Views and Functions in PostgreSQL
Views and Functions in PostgreSQL streamline SQL query management, with Views suited for fixed queries and Functions offering flexibility through parameter support. Views A View is a virtual table that stores an SQL query. It does not occupy disk space and always returns real-time data based on the stored query. However, Views do not allow the use of parameters, which limits their flexibility. Example of a View to summarize client data: CREATE VIEW client_summary AS ( SELECT client.id, client.name, client.contact, client_amount.total FROM client JOIN ( SELECT sale.client_id, SUM(sale.amount) AS total FROM sale GROUP BY sale.client_id ) AS client_amount ON client.id = client_amount.client_id WHERE client.id = 1 ); This View works only for a fixed client ID. In this case, 1. Functions Functions provide greater flexibility, accepting parameters and using the PL/pgSQL language. They can return values of different types, such as tables. Example of a Fun...