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SQL-Hackerrank-Challenge-Solutions

★ 12 Open GitHub ↗

Solutions for all SQL challenges on HackerRank executed on MySQL and MS SQL Server.

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# SQL HackerRank Challenge Solutions

## Description
Solutions for all easy, medium and hard SQL challenges on HackerRank executed on MySQL and MS SQL Server.

## Domains
### Basic Select

| Number| Challenges | Solutions|
| :---:| --- | :---: |
| 1 | [Revising the Select Query I](https://www.hackerrank.com/challenges/revising-the-select-query/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Revising-the-Select-Query-I.sql) |
| 2 | [Revising the Select Query II](https://www.hackerrank.com/challenges/revising-the-select-query-2/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Revising-the-Select-Query-II.sql) | 
| 3 | [Select All](https://www.hackerrank.com/challenges/select-all-sql/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Select-All.sql) |
| 4 | [Select By ID](https://www.hackerrank.com/challenges/select-by-id/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Select-By-ID.sql) | 
| 5 | [Japanese Cities' Attributes](https://www.hackerrank.com/challenges/japanese-cities-attributes/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Japanese-Cities'-Attributes.sql) | 
| 6 | [Japanese Cities' Names](https://www.hackerrank.com/challenges/japanese-cities-name/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Japanese-Cities'-Names.sql) | 
| 7 | [Weather Observation Station 1](https://www.hackerrank.com/challenges/weather-observation-station-1/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-1.sql) | 
| 8 | [Weather Observation Station 3](https://www.hackerrank.com/challenges/weather-observation-station-3/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-3.sql) | 
| 9 | [Weather Observation Station 4](https://www.hackerrank.com/challenges/weather-observation-station-4/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-4.sql) | 
| 10 | [Weather Observation Station 5](https://www.hackerrank.com/challenges/weather-observation-station-5/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-5.sql) | 
| 11 | [Weather Observation Station 6](https://www.hackerrank.com/challenges/weather-observation-station-6/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-6.sql) | 
| 12 | [Weather Observation Station 7](https://www.hackerrank.com/challenges/weather-observation-station-7/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-7.sql) | 
| 13 | [Weather Observation Station 8](https://www.hackerrank.com/challenges/weather-observation-station-8/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-8.sql) | 
| 14 | [Weather Observation Station 9](https://www.hackerrank.com/challenges/weather-observation-station-9/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-9.sql) | 
| 15 | [Weather Observation Station 10](https://www.hackerrank.com/challenges/weather-observation-station-10/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-10.sql) | 
| 16 | [Weather Observation Station 11](https://www.hackerrank.com/challenges/weather-observation-station-11/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-11.sql) | 
| 17 | [Weather Observation Station 12](https://www.hackerrank.com/challenges/weather-observation-station-12/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Weather-Observation-Station-12.sql) | 
| 18 | [Higher Than 75 Marks](https://www.hackerrank.com/challenges/more-than-75-marks/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Higher-Than-75-Marks.sql) | 
| 19 | [Employee Names](https://www.hackerrank.com/challenges/name-of-employees/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Employee-Names.sql) | 
| 20 | [Employee Salaries](https://www.hackerrank.com/challenges/salary-of-employees/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Select/Employee-Salaries.sql) |

### Advanced Select

| Number| Challenges | Solutions|
| :---:| --- | :---: | 
| 1 | [Type of Triangle](https://www.hackerrank.com/challenges/what-type-of-triangle/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Select/Type-of-Triangle.sql) | 
| 2 | [The PADS](https://www.hackerrank.com/challenges/the-pads/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Select/The-PADS.sql) |
| 3 | [Occupations](https://www.hackerrank.com/challenges/occupations/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Select/Occupations.sql) | 
| 4 | [Binary Tree Nodes](https://www.hackerrank.com/challenges/binary-search-tree-1/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Select/Binary-Tree-Nodes.sql) | 
| 5 | [New Companies](https://www.hackerrank.com/challenges/the-company/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Select/New-Companies.sql) |

### Aggregation

| Number| Challenges | Solutions|
| :---:| --- | :---: | 
| 1 | [Revising Aggregations - The Count Function](https://www.hackerrank.com/challenges/revising-aggregations-the-count-function/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Revising-Aggregations-The-Count-Function.sql) | 
| 2 | [Revising Aggregations - The Sum Function](https://www.hackerrank.com/challenges/revising-aggregations-sum/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Revising-Aggregations-The-Sum-Function.sql) | 
| 3 | [Revising Aggregations - Averages](https://www.hackerrank.com/challenges/revising-aggregations-the-average-function/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Revising-Aggregations-Averages.sql) |
| 4 | [Average Population](https://www.hackerrank.com/challenges/average-population/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Average-Population.sql) |
| 5 | [Japan Population](https://www.hackerrank.com/challenges/japan-population/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Japan-Population.sql) | 
| 6 | [Population Density Difference](https://www.hackerrank.com/challenges/population-density-difference/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Population-Density-Difference.sql) |
| 7 | [The Blunder](https://www.hackerrank.com/challenges/the-blunder/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/The-Blunder.sql) |
| 8 | [Top Earners](https://www.hackerrank.com/challenges/earnings-of-employees/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Top-Earners.sql) | 
| 9 | [Weather Observation Station 2](https://www.hackerrank.com/challenges/weather-observation-station-2/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-2.sql) | 
| 10 | [Weather Observation Station 13](https://www.hackerrank.com/challenges/weather-observation-station-13/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-13.sql) | 
| 11 | [Weather Observation Station 14](https://www.hackerrank.com/challenges/weather-observation-station-14/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-14.sql) | 
| 12 | [Weather Observation Station 15](https://www.hackerrank.com/challenges/weather-observation-station-15/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-15.sql) |
| 13 | [Weather Observation Station 16](https://www.hackerrank.com/challenges/weather-observation-station-16/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-16.sql) | 
| 14 | [Weather Observation Station 17](https://www.hackerrank.com/challenges/weather-observation-station-17/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-17.sql) | 
| 15 | [Weather Observation Station 18](https://www.hackerrank.com/challenges/weather-observation-station-18/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-18.sql) | 
| 16 | [Weather Observation Station 19](https://www.hackerrank.com/challenges/weather-observation-station-19/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-19.sql) | 
| 17 | [Weather Observation Station 20](https://www.hackerrank.com/challenges/weather-observation-station-20/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Aggregation/Weather-Observation-Station-20.sql) |

### Basic Join

| Number| Challenges | Solutions |
| :---:| --- | :---: | 
| 1 | [Population Census](https://www.hackerrank.com/challenges/asian-population/problem)| [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Join/Population-Census.sql) | 
| 2 | [African Cities](https://www.hackerrank.com/challenges/african-cities/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Join/African-Cities.sql) |
| 3 | [Average Population of Each Continent](https://www.hackerrank.com/challenges/average-population-of-each-continent/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Join/Average-Population-of-Each-Continent.sql) |
| 4 | [The Report](https://www.hackerrank.com/challenges/the-report/problem)| [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Join/The-Report.sql) | 
| 5 | [Top Competitors](https://www.hackerrank.com/challenges/full-score)| [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Join/Top-Competitors.sql) |
| 6 | [Ollivander's Inventory](https://www.hackerrank.com/challenges/harry-potter-and-wands/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Join/Ollivander's-Inventory.sql) |
| 7 | [Challenges](https://www.hackerrank.com/challenges/challenges/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Join/Challenges.sql) | 
| 8 | [Contest Leaderboard](https://www.hackerrank.com/challenges/contest-leaderboard/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Basic%20Join/Contest-Leaderboard.sql) |

### Advanced Join

| Number| Challenges | Solutions |
| :---:| --- | :---: |
| 1 | [SQL Project Planning](https://www.hackerrank.com/challenges/sql-projects/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Join/SQL-Project-Planning.sql) | 
| 2 | [Placements](https://www.hackerrank.com/challenges/placements/problem)| [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Join/Placements.sql) | 
| 3 | [Symmetric Pairs](https://www.hackerrank.com/challenges/symmetric-pairs/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Join/Symmetric-Pairs.sql) | 
| 4 | [Interviews](https://www.hackerrank.com/challenges/interviews/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Join/Interviews.sql) |
| 5 | [15 Days of Learning SQL](https://www.hackerrank.com/challenges/15-days-of-learning-sql/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Advanced%20Join/15-Days-of-Learning-SQL.sql) |

### Alternative Queries

| Number| Challenges |Solutions|
| :---:| --- | :---: | 
| 1 | [Draw The Triangle 1](https://www.hackerrank.com/challenges/draw-the-triangle-1/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Alternative%20Queries/Draw-The-Triangle-1.sql) | 
| 2 | [Draw The Triangle 2](https://www.hackerrank.com/challenges/draw-the-triangle-2/problem) | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Alternative%20Queries/Draw-The-Triangle-2.sql) | 
| 3 | [Print Prime Numbers](https://www.hackerrank.com/challenges/print-prime-numbers/problem)  | [Link](https://github.com/qanhnn12/SQL-Hackerrank-Challenge-Solutions/blob/main/Alternative%20Queries/Print-Prime-Numbers.sql) |

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