What does DISTINCT apply to with two columns?
QuizEasy-Medium
The employees table has 10 rows. In department 1, two people earn 95,000. In department 2, two people earn 64,000. Every other pair of department and salary is different. How many rows does this query return?
SELECT DISTINCT dept_id, salary FROM employees;
- 8: each different pair of dept_id and salary appears once
- 5: one row per department
- 10: DISTINCT applies only to dept_id, so salary rows stay
- An error: DISTINCT accepts only one column
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