--select *from uzivatel
--	where rok_narozeni <1990 and rok_narozeni>1980 or rok_narozeni%2 = 0;


--select distinct rok from vyrobek v, koupil k
-- where  v.vID = k.vID and
--        jmeno= 'lampa' ;

--select distinct v.jmeno,v.vID from vyrobek v, koupil k, uzivatel u
--where v.vID = k.vID and k.login = u.login and
--		u.mesto LIKE '%a'
--		order by v.jmeno DESC;


--select distinct v.jmeno from vyrobek v, koupil k, uzivatel u
--where v.vID = k.vID and k.login = u.login and
--	u.login = 'pepik'
--intersect
--select distinct v.jmeno from vyrobek v, koupil k, uzivatel u
--where v.vID = k.vID and k.login = u.login and u.login = 'vinetu';


--select distinct v.jmeno, v.vID from vyrobek v, koupil k
--where v.vID = k.vID and k.login = 'vinetu'
--except
--select distinct v.jmeno, v.vID from vyrobek v, koupil k
--where v.vID = k.vID and k.login = 'pepik';

--select distinct v.jmeno,v.vID from vyrobek v, koupil k, uzivatel u
--where v.vID = k.vID and k.login = u.login and
--	u.login = 'vinetu' and v.vID  NOT IN  (
--			select distinct v.vID from vyrobek v, koupil k, uzivatel u
--			where v.vID = k.vID and k.login = u.login and u.login = 'pepik');

--select distinct v.jmeno, v.vID from vyrobek v,koupil k
--where NOT EXISTS (select * from koupil k
--					where k.vID = v.vID);

--select distinct v.vID,v.jmeno from vyrobek v
--where v.vID in (select distinct k.vID from koupil k
--				group by k.vID having count(*)>1 )


--select distinct v.vID, v.jmeno from vyrobek v, koupil k1
--where v.vID = k1.vID and exists (select *from koupil k2
--								where k2.vID = k1.vID and
--								k2.login = k2.login and
--								k2.rok <>k1.rok)

select distinct v.jmeno from vyrobek v
where NOT exists (select *from koupil k
				  where k.cena>=v.aktualni_cena and k.vID =v.vID);