प्रत्येक समूह में शीर्ष तीन मान चुनें

इसे आजमाएं:

SELECT company, val FROM 
(
    SELECT *, ROW_NUMBER() OVER (PARTITION BY 
             company order by val DESC) AS Row_ID FROM com
) AS A
WHERE Row_ID < 4 ORDER BY company

--क्विक डेमो यहां...