Top Departments by Average Salary

MediumSQL · PostgreSQL

Problem

You are given employee and department data from an internal people analytics system. Write a PostgreSQL query to return the top three departments with the highest average employee salary, excluding departments that have fewer than five employees. The result should include the department name, employee count, and average salary, sorted by average salary from highest to lowest.

Output details

Return columns named department_name, employee_count, and avg_salary, in that order.
Exclude employees whose salary is NULL before calculating counts and averages.
Round avg_salary to exactly two decimal places.
Break equal average-salary ties by department_name in ascending alphabetical order.

Schema

departments

Column	Type	Description
department_idPK	INT	Unique identifier for a department
department_name	VARCHAR(100)	Department name

employees

Column	Type	Description
employee_idPK	INT	Unique identifier for an employee
employee_name	VARCHAR(100)	Employee full name
department_id	INT	Department assigned to the employee
salary	DECIMAL(10,2)	Employee salary

Tablesdepartmentsemployees

Output details

Return columns named department_name, employee_count, and avg_salary, in that order.
Exclude employees whose salary is NULL before calculating counts and averages.
Round avg_salary to exactly two decimal places.
Break equal average-salary ties by department_name in ascending alphabetical order.