project_16

WITH
i AS (
       SELECT DISTINCT p.id
       FROM people AS p
       LEFT OUTER JOIN company AS cmp ON p.company_id = cmp.id
       WHERE cmp.id IN (
                        SELECT DISTINCT c.id
                        FROM company as c
                        LEFT JOIN funding_round AS fr ON c.id = fr.company_id
                        WHERE c.status = 'closed'
                          AND c.id IN (SELECT DISTINCT company_id
                                       FROM funding_round
                                       WHERE is_first_round = 1
                                           AND is_last_round = 1))
)


SELECT task_15.id,
       COUNT(DISTINCT task_15.instituition) AS cnt
FROM (
      SELECT  DISTINCT i.id,
              e.instituition
      FROM education AS e
      INNER JOIN i ON e.person_id = i.id) AS task_15
GROUP BY task_15.id;


https://practicum.yandex.ru/trainer/sql-data-analyst/lesson/ce01e9d1-9867-4ecc-8912-e41892e7002f/task/9e867581-5f7c-4494-9094-359debe4aecb/