-- Database schema
| Manufacturers : Code [ INT ] primary_key , Name [ TEXT ] , Headquarter [ TEXT ] , Founder [ TEXT ] , Revenue [ INT ] | Products : Code [ INT ] primary_key , Name [ TEXT ] , Price [ INT ] , Manufacturer [ INT ] Products.Manufacturer = Manufacturers.Code |
-- -- What are the names and revenues of the companies with the highest revenues in each headquarter city?

SELECT name ,  max(revenue) ,  Headquarter FROM manufacturers GROUP BY Headquarter;