SQL Quest › SQL Interview Questions › Joins
Employees with Similar Salaries
Find all pairs of employees whose salaries are within 10% of each other but who are in different departments. Show emp1_name, emp1_salary, emp2_name, emp2_salary, and salary_diff (absolute difference). Only show each pair once (emp1 has the lower emp_id). Sort by salary_diff ascending. Non-equi joins (inequality conditions in JOIN) are asked at Google and Bloomberg because they test whether you can think beyond simple key matching.
Solve it in the browser editor →
Runs on SQLite in your browser, graded against the expected result, no signup. A wrong answer gets a diagnosis, not just "incorrect".
Schema
employees
| emp_id | name | department | position | salary | hire_date | manager_id | performance_rating |
|---|---|---|---|---|---|---|---|
| 1 | Alice Johnson | Engineering | Senior Developer | 95000 | 2019-03-15 | 5 | 4.5 |
| 2 | Bob Smith | Engineering | Developer | 75000 | 2020-06-01 | 1 | 3.8 |
| 3 | Carol Williams | Marketing | Marketing Manager | 85000 | 2018-09-20 | NULL | 4.2 |
Expected output: Pair appears because $73k is within 10% of $70k
Hint
Concepts
SELECT Self-Join Non-Equi Join ABS WHERE BETWEEN
Practise the topic: SQL practice questions · JOIN practice · Advanced SQL interview questions
In these company practice sets
A SQL Quest challenge matched to patterns reported for these companies — not a question any of them has published.
Related questions
Where would this cost you points in an interview?
Ten questions, no signup: a Skillmap across nine SQL skills and the one to fix first.
Take the readiness test