SQL Quest › SQL Interview Questions › Aggregation & Grouping
Department Performance Rate
Write a SQL query to calculate the percentage of high performers (rating >= 4.0) in each department. Return department and high_performer_rate (as percentage, rounded to 1 decimal). Order by high_performer_rate descending.
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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: high_performer_rate: 70.0%
Hint
Concepts
SELECT GROUP BY Aggregation CASE Rate Calculation
Practise the topic: SQL practice questions · GROUP BY exercises · CASE WHEN practice
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