SELECT Contests.contest_id, hacker_id, name,
    SUM(total_submissions),
    SUM(total_accepted_submissions)
    FROM
    Contests
    INNER JOIN Colleges ON Contests.contest_id = Colleges.contest_id
    INNER JOIN Challenges ON Colleges.college_id = Challenges.college_id
    INNER JOIN Submission_Stats ON Challenges.challenge_id = Submission_Stats.challenge_id
GROUP BY Contests.contest_id, hacker_id, name
ORDER BY Contests.contest_id;

SELECT Contests.contest_id, hacker_id, name,
    SUM(total_submissions),
    SUM(total_accepted_submissions)
    FROM
    Contests
    INNER JOIN Colleges ON Contests.contest_id = Colleges.contest_id
    INNER JOIN Challenges ON Colleges.college_id = Challenges.college_id
    INNER JOIN Submission_Stats ON Challenges.challenge_id = Submission_Stats.challenge_id
    INNER JOIN View_Stats ON Challenges.challenge_id = View_Stats.challenge_id
GROUP BY Contests.contest_id, hacker_id, name
ORDER BY Contests.contest_id;