Project Task 12

WITH

e AS   (SELECT  COUNT(DISTINCT(instituition)) AS No_of_instituitions,
                person_id
        FROM education
        GROUP BY person_id),

c AS   (SELECT  name,
                id
        FROM company)

SELECT  c.name,
        e.No_of_instituitions
FROM people AS p
    INNER JOIN e ON e.person_id = p.id
    INNER JOIN c ON c.id = p.company_id
ORDER BY e.No_of_instituitions DESC
LIMIT 5;