HW_5.sql

ELECT p.name, pr.name
FROM Products p RIGHT OUTER JOIN Producer pr ON p.id_producer = pr.id

SELECT p.name, c.name
FROM Products p RIGHT OUTER JOIN Category c ON p.id_category = c.id
WHERE p.name IS NULL 

SELECT name
FROM Region
EXCEPT 
SELECT rg.name
FROM Products p JOIN Producer pr ON p.id_producer = pr.id
JOIN Address a ON pr.id_adress = a.id
JOIN City c ON a.id_city = c.id
JOIN Region rg ON c.id_region = rg.id

SELECT name
FROM Category
EXCEPT
SELECT c.name
FROM Products p JOIN Category c ON p.id_category = c.id
JOIN Producer pr ON p.id_producer = pr.id
WHERE pr.name = 'Порося'