SELECT
 name,
 category,
  price,
  price * 1.10 AS price_with_markup,
  price * 1.20 AS price_with_vat,
  COALESCE(email_support, 'нет почты') AS status
FROM products_extended
WHERE in_stock = true
  AND category NOT IN ('smartwatch', 'ebook_reader')
  AND price BETWEEN 300 AND 1300;

SELECT
  name,
  category,
  email_support,
  price * 1.25 AS price_25,
  price > 1000 AS premium
FROM products_extended
WHERE (price < 150 OR price > 1200)
  AND email_support IS NOT NULL;

SELECT
  id,
  name,
  category,
  price
FROM products_extended
WHERE category IN ('smartphone', 'laptop', 'tablet')
  AND name NOT LIKE '%i%'
  AND price BETWEEN 500 AND 1300
ORDER BY id;

SELECT
  name,
  category,
  price,
  'нет поддержки' AS comment
FROM products_extended
WHERE in_stock = true
  AND email_support IS NULL
  AND price < 800;

SELECT
  name,
  category,
  price,
  price > 1000 AS premium
FROM products_extended
WHERE (name LIKE '%Pro' OR name LIKE '%X%')
  AND in_stock = true
  AND price > 700;