The Number of Employees Which Report to Each Employee | LeetCode

SELECT
    e.employee_id,
    e.name,
    COUNT(em.employee_id) AS reports_count,
    ROUND(AVG(em.age)) AS average_age
FROM Employees e
INNER JOIN Employees em ON e.employee_id = em.reports_to
GROUP BY e.employee_id
ORDER BY e.employee_id