SQL · Question 5 · Easy

SQL question 5

Table Employee:
id | name | dept | salary
1 | Asha | HR | 30000
2 | Ravi | IT | 50000
3 | Neha | IT | 60000
4 | Karan | Sales | NULL
5 | Priya | HR | 45000
6 | Vikram | IT | 50000

What is the output of the query?

SELECT COUNT(DISTINCT salary) FROM Employee;
  1. 6
  2. 5
  3. 4
  4. 3
Answer and explanation

Answer: C. 4

Explanation: COUNT(DISTINCT salary) ignores NULL and counts each value once. The distinct non-NULL salaries are 30000, 50000, 60000 and 45000, so the result is 4.

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