dva dotazy sql

Cau, neni mi jasny, proc mi tyhle dva dotazy davaji jiny vysledek:

SELECT MANAGER_ID, MIN(SALARY) FROM EMPLOYEES WHERE SALARY>6000 GROUP BY MANAGER_ID ORDER BY MIN(SALARY) DESC;

SELECT MANAGER_ID, MIN(SALARY) FROM EMPLOYEES GROUP BY MANAGER_ID HAVING MIN(SALARY)>6000 ORDER BY MIN(SALARY) DESC;

Nevite nekdo? Diky.
Pavel