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sql-hackerrank

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Solutions to the SQL HackerRank challenges.

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# HackerRank SQL Challenges

This repository contains my solutions to the [HackerRank SQL Challenges](https://www.hackerrank.com/domains/sql).

### Basic Select Challenges

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

### Advanced Select Challenges

| Number | Challenges                                                                              |                    Solutions                     |
|:---------------:|------------------------------------|:-----------------:|
|   1    | [Type of Triangle](https://www.hackerrank.com/challenges/what-type-of-triangle/problem) | [SQL](advanced_select/what-type-of-triangle.sql) |
|   2    | [The PADS](https://www.hackerrank.com/challenges/the-pads/problem)                      |       [SQL](advanced_select/the-pads.sql)        |
|   3    | [Occupations](https://www.hackerrank.com/challenges/occupations/problem)                |      [SQL](advanced_select/occupations.sql)      |

### Basic Join Challenges

| Number | Challenges                                                                                                                 |                         Solutions                          |
|:---------------:|--------------------------------------|:---------------:|
|   1    | [Asian Population](https://www.hackerrank.com/challenges/asian-population/problem)                                         |           [SQL](basic_join/asian-population.sql)           |
|   2    | [African Cities](https://www.hackerrank.com/challenges/african-cities/problem)                                             |            [SQL](basic_join/african-cities.sql)            |
|   3    | [Average Population of Each Continent](https://www.hackerrank.com/challenges/average-population-of-each-continent/problem) | [SQL](basic_join/average-population-of-each-continent.sql) |
|   4    | [The Report](https://www.hackerrank.com/challenges/the-report/submissions/code/94188063)                                   |              [SQL](basic_join/the-report.sql)              |
|   5    | [Top Competitors](https://www.hackerrank.com/challenges/full-score/problem)                                                |              [SQL](basic_join/full-score.sql)              |
|   6    | [Ollivander's Inventory](https://www.hackerrank.com/challenges/harry-potter-and-wands/problem)                             |        [SQL](basic_join/harry-potter-and-wands.sql)        |

### Aggregation Challenges

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

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