caute, jak by ste spravili relacnu ak mam v having agregacnu?
select department_id, count(*)
from hr.employees
where hire_date > '01.01.1995'
group by department_id
having count(*) < 10
MV1 <-- Sigma hire_date > '01.01.1995' (employees)
MV2 (department_id, pocet) <-- department_id, F count(*) (MV1)
MV3 (department_id, pocet) <-- Sigma F count(*) < 10 (MV2)
takto ?