Hackerrank-SQL

SQL solutions are updated here

Solutions

Basic Select

1. Revising the Select Query I
2. Revising the Select Query II
3. Select All
4. Select By ID
5. Japanese Cities' Attributes
6. Japanese Cities' Names
7. Weather Observation Station 1
8. Weather Observation Station 3
9. Weather Observation Station 4
10. Weather Observation Station 5
11. Weather Observation Station 6
12. Weather Observation Station 7
13. Weather Observation Station 8
14. Weather Observation Station 9
15. Weather Observation Station 10
16. Weather Observation Station 11
17. Weather Observation Station 12
18. Higher Than 75 Marks
19. Employee Names
20. Employee Salaries

Advance Select

1. Type of Triangle
2. The PADS
3. Occupations
4. Binary Tree Nodes
5. New Companies

Aggregation Challenge

1. Revising Aggregations - The Count Function
2. Revising Aggregations - The Sum Function
3. Revising Aggregations - Averages
4. Average Population
5. Japan Population
6. Population Density Difference
7. The Blunder
8. Top Earners
9. Weather Observation Station 2
10. Weather Observation Station 13
11. Weather Observation Station 14
12. Weather Observation Station 15
13. Weather Observation Station 16
14. Weather Observation Station 17
15. Weather Observation Station 18
16. Weather Observation Station 19
17. Weather Observation Station 20

Basic Join

1. Population Census
2. African Cities
3. Average Population of Each Continent
4. The Report
5. Top Competitors
6. Ollivander's Inventory
7. Challenges