SQL - Contest Leaderboard

You did such a great job helping Julia with her last coding contest challenge that she wants you to work on this one, too!

The total score of a hacker is the sum of their maximum scores for all of the challenges. Write a query to print the hacker_id, name, and total score of the hackers ordered by the descending score. If more than one hacker achieved the same total score, then sort the result by ascending hacker_id. Exclude all hackers with a total score of from your result.

Input Format

The following tables contain contest data:

• Hackers: The hacker_id is the id of the hacker, and name is the name of the hacker.

• Submissions: The submission_id is the id of the submission, hacker_id is the id of the hacker who made the submission, challenge_id is the id of the challenge for which the submission belongs to, and score is the score of the submission.

Sample Input

Hackers Table:

Submissions Table:

Sample Output

4071 Rose 191
74842 Lisa 174
84072 Bonnie 100
4806 Angela 89
26071 Frank 85
80305 Kimberly 67
49438 Patrick 43

Explanation

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Answer :

SELECT h.hacker_id, h.name, SUM(score) FROM (
    SELECT hacker_id, challenge_id, MAX(score) AS score FROM SUBMISSIONS
    GROUP BY hacker_id, challenge_id
)t 
JOIN Hackers h on t.hacker_id = h.hacker_id
GROUP BY h.hacker_id, h.name
HAVING SUM(score) > 0
ORDER BY SUM(score) desc, h.hacker_id