CREATE TABLE products (code NUMBER, name CLOB, price NUMBER, manufacturer NUMBER)
CREATE TABLE manufacturers (code NUMBER, name CLOB, headquarter CLOB, founder CLOB, revenue NUMBER)

How many different products are produced in each headquarter city?
SELECT COUNT(DISTINCT T1.name), T2.headquarter FROM products AS T1 JOIN manufacturers AS T2 ON T1.manufacturer = T2.code GROUP BY T2.headquarter
SELECT COUNT(DISTINCT "T1"."name"), "T2"."headquarter" FROM "products" "T1" JOIN "manufacturers" "T2" ON "T1"."manufacturer" = "T2"."code" GROUP BY "T2"."headquarter"