Собери портфолио аналитика, которое показывает работу.

SELECT title, price_eur
FROM meridian.catalog
WHERE category = 'Home & Kitchen'
  AND in_stock AND price_eur < 30
ORDER BY price_eur DESC
LIMIT 5

SELECT promo_code, COUNT(*) AS orders
FROM meridian.orders
WHERE status = 'paid'
GROUP BY promo_code

SELECT s.category, SUM(o.items_total_eur) AS sales_eur
FROM meridian.orders AS o
JOIN meridian.sellers AS s ON o.seller_id = s.seller_id
WHERE o.status = 'paid'
GROUP BY s.category
ORDER BY sales_eur DESC