SQL sorting does not follow group by statement, always uses primary key

Question

I have a SQL database with a table called staff, having following columns:

workerID (Prim.key), name, department, salary

I am

Answer 1

Try this:

SELECT s.workerID, s.name, s.department, s.salary
FROM staff s 
INNER JOIN (SELECT s.department, MAX(s.salary) AS biggest 
            FROM staff s GROUP BY s.department
          ) AS B ON s.department = B.department AND s.salary = B.biggest;

OR

SELECT s.workerID, s.name, s.department, s.salary
FROM (SELECT s.workerID, s.name, s.department, s.salary 
      FROM staff s 
      ORDER BY s.department, s.salary DESC
    ) AS s 
GROUP BY s.department;