Contest Leaderboard in SQL | HackerRank Programming Solutions | HackerRank SQL Solutions

Hello Programmers/Coders, Today we are going to share solutions of Programming problems of HackerRank of Programming Language SQL. At Each Problem with Successful submission with all Test Cases Passed, you will get an score or marks. And after solving maximum problems, you will be getting stars. This will highlight your profile to the recruiters.

In this post, you will find the solution for Contest Leaderboard in SQL-HackerRank Problem. We are providing the correct and tested solutions of coding problems present on HackerRank. If you are not able to solve any problem, then you can take help from our Blog/website.

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Introduction To SQL

SQL stands for Structured Query Language. SQL is used to create, remove, alter the database and database objects in a database management system and to store, retrieve, update the data in a database. SQL is a standard language for creating, accessing, manipulating database management system. SQL works for all modern relational database management systems, like SQL Server, Oracle, MySQL, etc.

  • It is a standard language for Relational Database System. It enables a user to create, read, update and delete relational databases and tables.
  • All the RDBMS like MySQL, Informix, Oracle, MS Access and SQL Server use SQL as their standard database language.
  • SQL allows users to query the database in a number of ways, using English-like statements.

Link for the ProblemContest Leaderboard SQL – Hacker Rank Solution

Contest Leaderboard SQL – Hacker Rank Solution

Problem:

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_idname, 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. 1458522826 a9ddd28469 ScreenShot2016 03 21at6.40.27AM
  • 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. 1458523022 771511df90 ScreenShot2016 03 21at6.40.37AM

Sample Input

Hackers Table: 1458523374 7ecc39010f ScreenShot2016 03 21at6.51.56AM

Submissions Table: 1458523388 0896218137 ScreenShot2016 03 21at6.51.45AM

Sample Output

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

Explanation

Hacker 4071 submitted solutions for challenges 19797 and 49593, so the total score .

Hacker 74842 submitted solutions for challenges 19797 and 63132, so the total score 

Hacker 84072 submitted solutions for challenges 49593 and 63132, so the total score .

The total scores for hackers 48062607180305, and 49438 can be similarly calculated.

Contest Leaderboard SQL – Hacker Rank Solution
SELECT X.hacker_id, 
(SELECT H.NAME FROM HACKERS H
                      WHERE H.HACKER_ID = X.HACKER_ID) NAME, 
SUM(X.SCORE) TOTAL_SCORE FROM 
  (SELECT HACKER_ID, MAX(SCORE) SCORE FROM SUBMISSIONS S
   GROUP BY 1, S.CHALLENGE_ID) X 
GROUP BY 1
HAVING TOTAL_SCORE > 0
ORDER BY TOTAL_SCORE DESC, HACKER_ID;

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