Sa se gaseasca toti angajatii care castiga  mai multdecat media  salariilor din departamentele in care lucreaza.

SELECT last_name, salary, department_id
    FROM  employee  e
    WHERE salary >
                                (SELECT AVG(salary)
                                        FROM Employees
                                        WHERE  department_id =e.department_id);

Sa se afiseze detalii despre acei angajati care  si-au schimbat  functiile (job-ul) de cel putin doua ori.
SELECT e.employee_id,last_name, e.job_id
    FROM employees e
    WHERE 2 <=     (SELECT  count (*)
                                    FROM job_history
                                    WHERE employee_id = e.employee_id);