--1
SELECT * FROM uzivatel WHERE rok_narozeni > 1980 and rok_narozeni < 1990 or (rok_narozeni % 2) = 0;
--2
SELECT distinct rok FROM vyrobek v, koupil k where v.vID = k.vID and v.jmeno = 'lampa';
--3
SELECT distinct v.vID, v.jmeno 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; 
--4
SELECT v.jmeno FROM vyrobek v, koupil k WHERE v.vID = k.vID and k.login  = 'vinetu'
INTERSECT
SELECT v.jmeno FROM vyrobek v, koupil k WHERE v.vID = k.vID and k.login  = 'pepik';
--nebo
SELECT v.jmeno FROM vyrobek v WHERE vID in (SELECT vID FROM koupil k WHERE k.login  = 'vinetu') and
									vID in (SELECT vID FROM koupil k WHERE k.login  = 'pepik');
--5
SELECT v.jmeno FROM vyrobek v WHERE vID in (SELECT vID FROM koupil k WHERE k.login  = 'vinetu') and
									vID not in (SELECT vID FROM koupil k WHERE k.login  = 'pepik');
--6
SELECT v.jmeno FROM vyrobek v WHERE v.vID not in (SELECT vID FROM koupil);
--7
SELECT distinct v1.vID, k1.login FROM vyrobek v1, koupil k1 WHERE v1.vID = k1.vID and 
exists (SELECT * FROM vyrobek v2, koupil k2 WHERE v2.vID = k2.vID and v1.vID = v2.vID and k1.login = k2.login and k2.rok <> k1.rok);
--8
SELECT v.jmeno FROM vyrobek v WHERE not exists (SELECT * FROM koupil k WHERE k.vID = v.vID and k.cena >= v.aktualni_cena);
--9
SELECT distinct u1.login FROM koupil k1, uzivatel u1 WHERE k1.login = u1.login and 
		not exists (SELECT * FROM koupil k2, uzivatel u2 WHERE k2.login = u2.login and k2.vID = k1.vID and u1.login <> u2.login and k2.cena < k1.cena);