{"id":9243547,"url":"https://github.com/Thomas-George-T/HackerRank-SQL-Challenges-Solutions","last_synced_at":"2025-08-17T07:31:49.475Z","repository":{"id":37625435,"uuid":"118511953","full_name":"Thomas-George-T/HackerRank-SQL-Challenges-Solutions","owner":"Thomas-George-T","description":"The solutions of all SQL hackerrank challenges using MySQL environment","archived":false,"fork":false,"pushed_at":"2024-04-30T13:25:25.000Z","size":65,"stargazers_count":729,"open_issues_count":2,"forks_count":218,"subscribers_count":19,"default_branch":"master","last_synced_at":"2024-12-17T10:38:11.364Z","etag":null,"topics":["challenge","hackerrank","hackerrank-challenges","hackerrank-solutions","hackerrank-sql","hackerrank-sql-solutions","mysql","mysql-environment","problem-solving","select-challenges","solutions","sql","sql-challenges","tutorials"],"latest_commit_sha":null,"homepage":"","language":"SQL","has_issues":false,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/Thomas-George-T.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE.md","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2018-01-22T20:36:28.000Z","updated_at":"2024-12-15T20:43:34.000Z","dependencies_parsed_at":"2023-02-17T20:01:04.198Z","dependency_job_id":"83563ea7-fd0a-47d3-aa46-9a03c9e78286","html_url":"https://github.com/Thomas-George-T/HackerRank-SQL-Challenges-Solutions","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/Thomas-George-T/HackerRank-SQL-Challenges-Solutions","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Thomas-George-T%2FHackerRank-SQL-Challenges-Solutions","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Thomas-George-T%2FHackerRank-SQL-Challenges-Solutions/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Thomas-George-T%2FHackerRank-SQL-Challenges-Solutions/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Thomas-George-T%2FHackerRank-SQL-Challenges-Solutions/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/Thomas-George-T","download_url":"https://codeload.github.com/Thomas-George-T/HackerRank-SQL-Challenges-Solutions/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Thomas-George-T%2FHackerRank-SQL-Challenges-Solutions/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":270820680,"owners_count":24651515,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","status":"online","status_checked_at":"2025-08-17T02:00:09.016Z","response_time":129,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["challenge","hackerrank","hackerrank-challenges","hackerrank-solutions","hackerrank-sql","hackerrank-sql-solutions","mysql","mysql-environment","problem-solving","select-challenges","solutions","sql","sql-challenges","tutorials"],"created_at":"2024-05-08T00:09:58.277Z","updated_at":"2025-08-17T07:31:49.114Z","avatar_url":"https://github.com/Thomas-George-T.png","language":"SQL","readme":"![GitHub](https://img.shields.io/github/license/Thomas-George-T/HackerRank-SQL-Challenges-Solutions?style=flat)\n![GitHub top language](https://img.shields.io/github/languages/top/Thomas-George-T/HackerRank-SQL-Challenges-Solutions?style=flat)\n![GitHub last commit](https://img.shields.io/github/last-commit/Thomas-George-T/HackerRank-SQL-Challenges-Solutions?style=flat)\n![ViewCount](https://views.whatilearened.today/views/github/Thomas-George-T/HackerRank-SQL-Challenges-Solutions.svg?cache=remove)\n\n\u003cp align=\"center\"\u003e  \n\t\u003cbr\u003e\n\t\u003ca href=\"https://www.hackerrank.com/Thomas_George_T\"\u003e\n        \u003cimg height=100 src=\"https://hrcdn.net/community-frontend/assets/brand/logo-new-white-green-a5cb16e0ae.svg\"\u003e \n    \u003c/a\u003e\n    \u003cbr\u003e\n    \u003cbr\u003e\n\u003c/p\u003e\n\n## Description\nThe solutions of all the SQL challenges for all easy, medium and hard challenges on HackerRank executed on MySQL environment compiled with helpful Resources \u0026 references related to the challenges.\n\n## Domains\n\n### Basic Select Challenges\n\n| Number | Challenges | Solutions |\n|:------:|------------|:---------:|\n| 1 | [Revising the Select Query I](https://www.hackerrank.com/challenges/revising-the-select-query/problem) | [SQL](Basic%20Select/Revising-the-select-Query-1.sql)\n| 2 | [Revising the Select Query II](https://www.hackerrank.com/challenges/revising-the-select-query-2/problem) | [SQL](Basic%20Select/Revising-the-select-Query-2.sql)\n| 3 | [Select All](https://www.hackerrank.com/challenges/select-all-sql/problem) | [SQL](Basic%20Select/Select-All.sql)\n| 4 | [Select By ID](https://www.hackerrank.com/challenges/select-by-id/problem) | [SQL](Basic%20Select/Select-By-ID.sql)\n| 5 | [Japanese Cities' Attributes](https://www.hackerrank.com/challenges/japanese-cities-attributes/problem) | [SQL](Basic%20Select/Japanese-Cities'-Attributes.sql)\n| 6 | [Japanese Cities' Names](https://www.hackerrank.com/challenges/japanese-cities-name/problem) | [SQL](Basic%20Select/Japanese-Cities'-Names.sql)\n| 7 | [Weather Observation Station 1](https://www.hackerrank.com/challenges/weather-observation-station-1/problem) | [SQL](Basic%20Select/Weather-Observation-Station-1.sql)\n| 8 | [Weather Observation Station 3](https://www.hackerrank.com/challenges/weather-observation-station-3/problem) | [SQL](Basic%20Select/Weather-Observation-Station-3.sql)\n| 9 | [Weather Observation Station 4](https://www.hackerrank.com/challenges/weather-observation-station-4/problem) | [SQL](Basic%20Select/Weather-Observation-Station-4.sql)\n| 10| [Weather Observation Station 5](https://www.hackerrank.com/challenges/weather-observation-station-5/problem) | [SQL](Basic%20Select/Weather-Observation-Station-5.sql)\n| 11| [Weather Observation Station 6](https://www.hackerrank.com/challenges/weather-observation-station-6/problem) | [SQL](Basic%20Select/Weather-Observation-Station-6.sql)\n| 12| [Weather Observation Station 7](https://www.hackerrank.com/challenges/weather-observation-station-7/problem) | [SQL](Basic%20Select/Weather-Observation-Station-7.sql)\n| 13| [Weather Observation Station 8](https://www.hackerrank.com/challenges/weather-observation-station-8/problem) | [SQL](Basic%20Select/Weather-Observation-Station-8.sql)\n| 14| [Weather Observation Station 9](https://www.hackerrank.com/challenges/weather-observation-station-9/problem) | [SQL](Basic%20Select/Weather-Observation-Station-9.sql)\n| 15| [Weather Observation Station 10](https://www.hackerrank.com/challenges/weather-observation-station-10/problem) | [SQL](Basic%20Select/Weather-Observation-Station-10.sql)\n| 16| [Weather Observation Station 11](https://www.hackerrank.com/challenges/weather-observation-station-11/problem) | [SQL](Basic%20Select/Weather-Observation-Station-11.sql)\n| 17| [Weather Observation Station 12](https://www.hackerrank.com/challenges/weather-observation-station-12/problem) | [SQL](Basic%20Select/Weather-Observation-Station-12.sql)\n| 18| [Higher Than 75 Marks](https://www.hackerrank.com/challenges/more-than-75-marks/problem) | [SQL](Basic%20Select/Higher-Than-75-Marks.sql)\n| 19| [Employee Names](https://www.hackerrank.com/challenges/name-of-employees/problem) | [SQL](Basic%20Select/Employee-Names.sql)\n| 20| [Employee Salaries](https://www.hackerrank.com/challenges/salary-of-employees/problem) | [SQL](Basic%20Select/Employee-Salaries.sql)\n\n### Advanced Select Challenges\n\n| Number | Challenges | Solutions |\n|:------:|------------|:---------:|\n| 1 |[Type of Triangle](https://www.hackerrank.com/challenges/what-type-of-triangle/problem) | [SQL](Advanced%20Select/Type%20of%20Triangle.sql) |\n| 2 |[The PADS](https://www.hackerrank.com/challenges/the-pads/problem) | [SQL](Advanced%20Select/The%20PADS.sql) |\n| 3 |[Occupations](https://www.hackerrank.com/challenges/occupations/problem) | [SQL](Advanced%20Select/Occupations.sql) |\n| 4 |[Binary Tree Nodes](https://www.hackerrank.com/challenges/binary-search-tree-1/problem) | [SQL](Advanced%20Select/Binary%20Tree%20Nodes.sql)|\n| 5 |[New Companies](https://www.hackerrank.com/challenges/the-company/problem) | [SQL](Advanced%20Select/New%20Companies.sql) |\n\n\n\n### Aggregation Challenges\n\n| Number | Challenges | Solutions |\n|:------:|------------|:---------:|\n| 1 | [Revising Aggregations - The Count Function](https://www.hackerrank.com/challenges/revising-aggregations-the-count-function/problem) | [SQL](Aggregation/Revising%20Aggregations%20-%20The%20Count%20Function.sql) | \n| 2 | [Revising Aggregations - The Sum Function](https://www.hackerrank.com/challenges/revising-aggregations-sum/problem) | [SQL](Aggregation/Revising%20Aggregations%20-%20The%20Sum%20Function.sql)                    |\n| 3 | [Revising Aggregations - Averages](https://www.hackerrank.com/challenges/revising-aggregations-the-average-function/problem) | [SQL](Aggregation/Revising%20Aggregations%20-%20Averages.sql)                       |\n| 4 | [Average Population](https://www.hackerrank.com/challenges/average-population/problem) | [SQL](Aggregation/Average%20Population.sql)                                                                               |\n| 5 | [Japan Population](https://www.hackerrank.com/challenges/japan-population/problem) | [SQL](Aggregation/Japan%20Population.sql)                                                                                     |\n| 6 | [Population Density Difference](https://www.hackerrank.com/challenges/population-density-difference/problem) | [SQL](Aggregation/Population%20Density%20Difference.sql)                                            |\n| 7 | [The Blunder](https://www.hackerrank.com/challenges/the-blunder/problem) | [SQL](Aggregation/The%20Blunder.sql)  \n| 8 | [Top Earners](https://www.hackerrank.com/challenges/earnings-of-employees/problem) | [SQL](Aggregation/Top%20Earners.sql) |         \n| 9 | [Weather Observation Station 2](https://www.hackerrank.com/challenges/weather-observation-station-2/problem) | [SQL](Aggregation/Weather%20Observation%20Station%202.sql) |\n| 10| [Weather Observation Station 13](https://www.hackerrank.com/challenges/weather-observation-station-13/problem) | [SQL](Aggregation/Weather%20Observation%20Station%2013.sql) |\n| 11| [Weather Observation Station 14](https://www.hackerrank.com/challenges/weather-observation-station-14/problem) | [SQL](Aggregation/Weather%20Observation%20Station%2014.sql) |\n| 12| [Weather Observation Station 15](https://www.hackerrank.com/challenges/weather-observation-station-15/problem) | [SQL](Aggregation/Weather%20Observation%20Station%2015.sql) |\n| 13| [Weather Observation Station 16](https://www.hackerrank.com/challenges/weather-observation-station-16/problem) | [SQL](Aggregation/Weather%20Observation%20Station%2016.sql) |\n| 14| [Weather Observation Station 17](https://www.hackerrank.com/challenges/weather-observation-station-17/problem) | [SQL](Aggregation/Weather%20Observation%20Station%2017.sql) |\n| 15| [Weather Observation Station 18](https://www.hackerrank.com/challenges/weather-observation-station-18/problem) | [SQL](Aggregation/Weather%20Observation%20Station%2018.sql) |\n| 16| [Weather Observation Station 19](https://www.hackerrank.com/challenges/weather-observation-station-19/problem) | [SQL](Aggregation/Weather%20Observation%20Station%2019.sql) |\n| 17| [Weather Observation Station 20](https://www.hackerrank.com/challenges/weather-observation-station-20/problem) | [SQL](Aggregation/Weather%20Observation%20Station%2020.sql) |\n\n\n### Basic Join\n\n| Number | Challenges | Solutions |\n|:------:|------------|:---------:|\n| 1 | [Asian Population](https://www.hackerrank.com/challenges/asian-population/problem) | [SQL](Basic%20Join/Asian%20Population.sql) |\n| 2 | [African Cities](https://www.hackerrank.com/challenges/african-cities/problem) | [SQL](Basic%20Join/African%20Cities.sql) |\n| 3 | [Average Population of Each Continent](https://www.hackerrank.com/challenges/average-population-of-each-continent/problem) | [SQL](Basic%20Join/Average%20Population%20of%20Each%20Continent.sql) |\n| 4 | [The Report](https://www.hackerrank.com/challenges/the-report/submissions/code/94188063) | [SQL](Basic%20Join/The%20Report.sql) |\n| 5 | [Top Competitors](https://www.hackerrank.com/challenges/full-score/problem) | [SQL](Basic%20Join/Top%20Competitors.sql) |\n| 6 | [Ollivander's Inventory](https://www.hackerrank.com/challenges/harry-potter-and-wands/problem) | [SQL](Basic%20Join/Ollivander's%20Inventory.sql) |\n| 7 | [Challenges](https://www.hackerrank.com/challenges/challenges/problem) | [SQL](Basic%20Join/Challenges.sql) |\n| 8 | [Contest Leaderboard](https://www.hackerrank.com/challenges/contest-leaderboard/problem) | [SQL](/Basic%20Join/Contest%20Leaderboard.sql) |\n\n### Advanced Join\n\n| Number |                                     Challenges                                     |                      Solutions                     |\n|:------:|:----------------------------------------------------------------------------------:|:--------------------------------------------------:|\n|    1   | [SQL Project Planning](https://www.hackerrank.com/challenges/sql-projects/problem) | [SQL](ADVANCE%20JOIN/SQL%20PROJECT%20PLANNING.sql) |\n|    2   | [Placements](https://www.hackerrank.com/challenges/placements/problem)             | [SQL](ADVANCE%20JOIN/Placements.sql)               |\n\n## References\n\n- [Instant SQL Formatter](http://www.dpriver.com/pp/sqlformat.htm)\n- [Variables in MySQL](https://stackoverflow.com/a/11754790)\n- [Median in MySQL](https://stackoverflow.com/a/7263925)\n\n## Features \u0026 Mentions\nThis project was featured in [laptrinhx](https://laptrinhx.com/the-solutions-of-all-sql-hackerrank-challenges-executed-on-mysql-environment-545160427/). Thank you for the listing!\n\n## License\nThis repository is licensed under MIT License - see [License](LICENSE.md) for more details\n","funding_links":[],"categories":["[SQL](#sql)"],"sub_categories":[],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2FThomas-George-T%2FHackerRank-SQL-Challenges-Solutions","html_url":"https://awesome.ecosyste.ms/projects/github.com%2FThomas-George-T%2FHackerRank-SQL-Challenges-Solutions","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2FThomas-George-T%2FHackerRank-SQL-Challenges-Solutions/lists"}