MAX funktion brugt med GROUP BY klausul

Først skal du få den maksimale løn for hver afdeling:

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

så kan du slutte denne underforespørgsel tilbage til testtabellen:

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