Fungsi MAX digunakan dengan klausa GROUP BY

Pertama, Anda harus mendapatkan gaji maksimum untuk setiap departemen:

SELECT department, max(salary) as max_salary
FROM test
GROUP BY department

maka Anda dapat menggabungkan kembali subquery ini ke tabel pengujian:

SELECT t.*
FROM
  test t INNER JOIN (
    SELECT department, max(salary) as max_salary
    FROM test
    GROUP BY department
  ) d ON t.department=d.department AND t.salary=d.max_salary