CREATE TABLE manufacturers (Headquarter VARCHAR(255), code VARCHAR(255)); CREATE TABLE products (name VARCHAR(255), Manufacturer VARCHAR(255))
Find the number of different products that are produced by companies at different headquarter cities.
    
SQL: SELECT COUNT(DISTINCT T1.name), T2.Headquarter FROM products AS T1 JOIN manufacturers AS T2 ON T1.Manufacturer = T2.code GROUP BY T2.Headquarter