Salary Statistics by Department - Medium SQL Grouping Interview Problem

Problem

HR wants a summary of compensation by department. Using the employees table, return department, headcount, avg_salary (rounded to 2 decimal places), min_salary, and max_salary for each department, ordered alphabetically.

Schema

employees

column	type
id	INTEGER
name	TEXT
department	TEXT
salary	INTEGER

Sample Data

id	name	department	salary
1	Alice	Engineering	120000
2	Bob	Engineering	100000
3	Carol	HR	65000
4	Dave	Marketing	80000
5	Eve	Marketing	90000

Expected Output

department	headcount	avg_salary	min_salary	max_salary
Engineering	2	110000.00	100000	120000
HR	1	65000.00	65000	65000
Marketing	2	85000.00	80000	90000

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