Data Science Skills
ASKED IN INTERVIEWLinked In
Problem Statement
LinkedIn is helping recruiters find the best Data Science candidates. You need to identify candidates who possess all three of the following skills: Python, Tableau, and PostgreSQL.
Write an SQL query to retrieve the candidate_id of these individuals.
Rules:
- A candidate must have all three specific skills to be included.
- Output column: candidate_id.
- Results must be sorted by candidate_id in ascending order.
Tests your understanding of
Relational Division, Filtering and Aggregation
Input Tables
candidates
| candidate_id(INTEGER) | skill(VARCHAR) |
|---|---|
| 101 | Python |
| 101 | Tableau |
| 101 | PostgreSQL |
| 102 | Python |
| 102 | Java |
| 103 | Python |
| 103 | Tableau |
| 103 | PostgreSQL |
| 103 | R |
skills_master
| skill_id(INTEGER) | skill_name(VARCHAR) |
|---|---|
| 1 | Python |
| 2 | Tableau |
| 3 | PostgreSQL |
candidate_metadata
| candidate_id(INTEGER) | years_exp(INTEGER) |
|---|---|
| 101 | 3 |
| 102 | 5 |
| 103 | 2 |
Expected Output
| candidate_id(INTEGER) |
|---|
| 101 |
| 103 |
Tags
EasyASKED IN INTERVIEWRelational DivisionFilteringAggregation
10-15 min
62%