CREATE TABLE invoices (billing_country VARCHAR, total INT)

A list of the top 8 countries by gross/total invoice size. List country name and gross invoice size.
SELECT billing_country, SUM(total) FROM invoices GROUP BY billing_country ORDER BY SUM(total) DESC LIMIT 8
SELECT "billing_country", SUM("total") FROM "invoices" GROUP BY "billing_country" ORDER BY SUM("total") DESC NULLS LAST LIMIT 8