Hackerrank SQL problems

Skills Certification:
Basic SQL
Intermediate SQL

This is a repository of solved HackerRank SQL problems

Basic Select

Challenge	Solution
Revising the Select Query	MySQL
Revising the Select Query II	MySQL
Select All	MySQL
Select by ID	MySQL
Japanese Cities'Attributes	MySQL
Japanese Cities' Names	MySQL
Weather Observation Station 1	MySQL
Weather Observation Station 3	MySQL
Weather Observation Station 4	MySQL
Weather Observation Station 5	MySQL
Weather Observation Station 6	MySQL
Weather Observation Station 7	MySQL
Weather Observation Station 8	MySQL
Weather Observation Station 9	MySQL
Weather Observation Station 10	MySQL
Weather Observation Station 11	MySQL
Weather Observation Station 12	MySQL
Higher than 75 Marks	MySQL
Employee Names	MySQL
Employee Salaries	MySQL

Advanced Select

Challenge	Solution
Type of Triangle	MySQL
The PADS	MySQL
Binary Tree Nodes	MySQL
New Companies	MySQL

Aggregation

Challenge	Solution
Revising Aggregation - The Count Function	MySQL
Revising Aggregation - The Sum Function	MySQL
Revising Aggregations - Averages	MySQL
Average Population	MySQL
Japan Population	MySQL
The Blunder	MySQL
Top Earners	MySQL
Weather Observation Station 2	MySQL
Weather Observation Station 13	MySQL
Weather Observation Station 14	MySQL
Weather Observation Station 15	MySQL
Weather Observation Station 16	MySQL
Weather Observation Station 17	MySQL
Weather Observation Station 18	MySQL
Weather Observation Station 19	MySQL
Weather Observation Station 20	MySQL

Basic Join

Challenge	Solution
Population Census	MySQL
African Cities	MySQL
Average Population of Each Continent	MySQL
The Report	MySQL
Top Competitors	MySQL
Ollivander's Inventory	MySQL
Challenges	MySQL
Contest Leaderboard	MySQL

Advanced Join

Challenge	Solution
Placements	MySQL
Symmetric Pairs	MySQL

Alternative Queries

Challenge	Solution
Draw the Triangle 1	MS SQL
Draw the Triangle 2	MS SQL