SQL | HackerRank Solutions

Answers to every SQL puzzle.

For beginners, try:
- Practical SQL, 2nd Edition: A Beginner's Guide to Storytelling with Data 2nd Edition

Revising the Select Query I: 0:00
Revising the Select Query II: 0:10
Select All: 0:20
Select By ID: 0:30
Japanese Cities' Attributes: 0:40
Japanese Cities' Names: 0:50
Weather Observation Station 1: 1:00
Weather Observation Station 3: 1:10
Weather Observation Station 4: 1:20
Weather Observation Station 5: 1:30
Weather Observation Station 6: 1:40
Weather Observation Station 7: 1:50
Weather Observation Station 8: 2:00
Weather Observation Station 9: 2:10
Weather Observation Station 10: 2:20
Weather Observation Station 11: 2:30
Weather Observation Station 12: 2:40
Higher Than 75 Marks: 2:50
Employee Names: 3:00
Employee Salaries: 3:10
Type of Triangle: 3:20
The PADS: 3:30
Occupations: 3:40
Binary Tree Nodes: 3:50
New Companies: 4:00
Revising Aggregations - The Count Function: 4:10
Revising Aggregations - The Sum Function: 4:20
Revising Aggregations - Averages: 4:30
Average Population: 4:40
Japan Population: 4:50
Population Density Difference: 5:00
The Blunder: 5:10
Top Earners: 5:20
Weather Observation Station 2: 5:30
Weather Observation Station 13: 5:40
Weather Observation Station 14: 5:50
Weather Observation Station 15: 6:00
Weather Observation Station 16: 6:10
Weather Observation Station 17: 6:20
Weather Observation Station 18: 6:30
Weather Observation Station 19: 6:40
Weather Observation Station 20: 6:50
Asian Population: 7:00
African Cities: 7:10
Average Population of Each Continent: 7:20
The Report: 7:30
Top Competitors: 7:40
Ollivander's Inventory: 7:50
Challenges: 8:00
Contest Leaderboard: 8:10
Projects: 8:20
Placements: 8:30
Symmetric Pairs: 8:40
Interviews: 8:50
15 Days of Learning SQL: 9:00
Draw The Triangle 1: 9:10
Draw The Triangle 2: 9:20
Print Prime Numbers: 9:30