הוספת נתונים: INSERT

INSERT INTO tabella (col1, col2, …)
VALUES (val1, val2, …);

INSERT INTO customers (first_name, last_name, email, city, country, signed_up_on)
VALUES ('Marco', 'Bianchi', 'marco.bianchi@example.com', 'Verona', 'Italia', '2025-07-15');

INSERT INTO categories (name, parent_id) VALUES
  ('Gaming',         1),
  ('Smart Home',     1),
  ('Cucina vegana',  8);

INSERT INTO categories (name, parent_id)
VALUES ('Gaming', 1)
RETURNING id, name;

-- Va bene: id è SERIAL (auto), country ha NOT NULL ma forniamo tutti i campi
INSERT INTO customers (first_name, last_name, email, city, country, signed_up_on)
VALUES ('Olivia', 'Marini', 'olivia.marini@example.com', 'Bari', 'Italia', '2025-07-20');

-- Errore: first_name è NOT NULL e non è fornito
INSERT INTO customers (last_name, email, city, country, signed_up_on)
VALUES ('Marini', 'olivia.marini@example.com', 'Bari', 'Italia', '2025-07-20');