/* 1
SELECT login
FROM uzivatel
WHERE rok_narozeni
between 1980 AND 1990
OR rok_narozeni % 2 = 0
*/
/* 2
SELECT
DISTINCT k.rok
FROM koupil k, vyrobek v
WHERE k.vID = v.vID
AND v.jmeno = 'lampa'
*/

/* 3
SELECT
DISTINCT
v.jmeno
FROM vyrobek v, koupil k, uzivatel u
WHERE k.vID = v.vID
AND u.mesto like '%a'
ORDER BY v.jmeno DESC
*/

/* 4
SELECT
DISTINCT v.jmeno
FROM vyrobek v, koupil k
WHERE k.vID = v.vID
AND k.login = 'vinetu'
INTERSECT
SELECT
DISTINCT v.jmeno
FROM vyrobek v, koupil k
WHERE k.vID = v.vID
AND k.login = 'pepik'
*/

/* 5
SELECT
DISTINCT v.jmeno
FROM vyrobek v, koupil k
WHERE k.vID = v.vID
AND k.login = 'vinetu'
EXCEPT
SELECT
DISTINCT v.jmeno
FROM vyrobek v, koupil k
WHERE k.vID = v.vID
AND k.login = 'pepik'

*/

SELECT
DISTINCT jmeno
FROM vyrobek
EXCEPT
SELECT
DISTINCT v.jmeno
FROM vyrobek v, koupil k
WHERE v.vID = k.vID