Description

The solutions of all the Hackerrank SQL challenges for all easy, medium and hard challenges executed on Oracle environment.

Domains

1. Basic Select

Number	Challenges	Solutions	Difficulty	Max Score
1	Revising the Select Query I	SQL	Easy	10
2	Revising the Select Query II	SQL	Easy	10
3	Select All	SQL	Easy	10
4	Select By ID	SQL	Easy	10
5	Japanese Cities' Attributes	SQL	Easy	10
6	Japanese Cities' Names	SQL	Easy	10
7	Weather Observation Station 1	SQL	Easy	15
8	Weather Observation Station 3	SQL	Easy	10
9	Weather Observation Station 4	SQL	Easy	10
10	Weather Observation Station 5	SQL	Easy	30
11	Weather Observation Station 6	SQL	Easy	10
12	Weather Observation Station 7	SQL	Easy	10
13	Weather Observation Station 8	SQL	Easy	15
14	Weather Observation Station 9	SQL	Easy	10
15	Weather Observation Station 10	SQL	Easy	10
16	Weather Observation Station 11	SQL	Easy	15
17	Weather Observation Station 12	SQL	Easy	15
18	Higher Than 75 Marks	SQL	Easy	15
19	Employee Names	SQL	Easy	10
20	Employee Salaries	SQL	Easy	10

2. Advanced Select

Number	Challenges	Solutions	Difficulty	Max Score
1	Type of Triangle	SQL	Easy	20
2	The PADS	SQL	Medium	30
3	Occupations	SQL	Medium	30
4	Binary Tree Nodes	SQL	Medium	30
5	New Companies	SQL	Medium	30

3. Aggregation

Number	Challenges	Solutions	Difficulty	Max Score
1	Revising Aggregations - The Count Function	SQL	Easy	10
2	Revising Aggregations - The Sum Function	SQL	Easy	10
3	Revising Aggregations - Averages	SQL	Easy	10
4	Average Population	SQL	Easy	10
5	Japan Population	SQL	Easy	10
6	Population Density Difference	SQL	Easy	10
7	The Blunder	SQL	Easy	15
8	Top Earners	SQL	Easy	20
9	Weather Observation Station 2	SQL	Easy	15
10	Weather Observation Station 13	SQL	Easy	10
11	Weather Observation Station 14	SQL	Easy	10
12	Weather Observation Station 15	SQL	Easy	15
13	Weather Observation Station 16	SQL	Easy	10
14	Weather Observation Station 17	SQL	Easy	15
15	Weather Observation Station 18	SQL	Medium	25
16	Weather Observation Station 19	SQL	Medium	30
17	Weather Observation Station 20	SQL	Medium	40

4. Basic Join

Number	Challenges	Solutions	Difficulty	Max Score
1	Population Census	SQL	Easy	10
2	African Cities	SQL	Easy	10
3	Average Population of Each Continent	SQL	Easy	10
4	The Report	SQL	Medium	20
5	Top Competitors	SQL	Medium	30
6	Ollivander's Inventory	NA	Medium	30
7	Challenges	NA	Medium	30
8	Contest Leaderboard	NA	Medium	30

5. Advanced Join

Number	Challenges	Solutions	Difficulty	Max Score
1	SQL Project Planning	NA	Medium	40
2	Placements	NA	Medium	40
3	Symmetric Pairs	NA	Medium	40
4	Interviews	NA	Hard	50
5	15 Days of Learning SQL	NA	Hard	50

6. Alternative Queries

Number	Challenges	Solutions	Difficulty	Max Score
1	Draw The Triangle 1	SQL	Easy	25
2	Draw The Triangle 2	SQL	Easy	25
3	Print Prime Numbers	SQL	Medium	40

References

• Alternative Queries
• Aggregate Function

License

This repository is licensed under MIT License - see License for more details