# 2853. Highest Salaries Difference

## Description

Table: Salaries

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| emp_name    | varchar |
| department  | varchar |
| salary      | int     |
+-------------+---------+
(emp_name, department) is the primary key (combination of unique values) for this table.
Each row of this table contains emp_name, department and salary. There will be at least one entry for the engineering and marketing departments.


Write a solution to calculate the difference between the highest salaries in the marketing and engineering department. Output the absolute difference in salaries.

Return the result table.

The result format is in the following example.

Example 1:

Input:
Salaries table:
+----------+-------------+--------+
| emp_name | department  | salary |
+----------+-------------+--------+
| Kathy    | Engineering | 50000  |
| Roy      | Marketing   | 30000  |
| Charles  | Engineering | 45000  |
| Jack     | Engineering | 85000  |
| Benjamin | Marketing   | 34000  |
| Anthony  | Marketing   | 42000  |
| Edward   | Engineering | 102000 |
| Terry    | Engineering | 44000  |
| Evelyn   | Marketing   | 53000  |
| Arthur   | Engineering | 32000  |
+----------+-------------+--------+
Output:
+-------------------+
| salary_difference |
+-------------------+
| 49000             |
+-------------------+
Explanation:
- The Engineering and Marketing departments have the highest salaries of 102,000 and 53,000, respectively. Resulting in an absolute difference of 49,000.


## Solutions

Solution 1: GROUP BY Clause

We can first calculate the highest salary for each department, and then calculate the difference between the two highest salaries.

• # Write your MySQL query statement below
SELECT MAX(s) - MIN(s) AS salary_difference
FROM
(
SELECT MAX(salary) AS s
FROM Salaries
GROUP BY department
) AS t;