--Zad4
SELECT INTERVAL '101-11' YEAR(3) TO MONTH AS "Przedzial A",
  INTERVAL '25 3:5:36.6'DAY(2) TO SECOND  AS "Przedzial B",
  TIMESTAMP '101-11-25 3:05:36.6'         AS "Razem"
FROM dual;

--Zad6
SELECT CURRENT_TIMESTAMP - INTERVAL '117 8:9:0' DAY(3) TO SECOND,
  CURRENT_TIMESTAMP      - INTERVAL '19-10' YEAR(3) TO MONTH
FROM dual;

--Zad9
SELECT * FROM studenci
WHERE
  EXTRACT(MONTH FROM data_urodzenia) = EXTRACT(MONTH, FROM CURRENT_DATE) AND
  EXTRACT(DAY FROM data_urodzenia) = EXTRACT(DAY, FROM CURRENT_DATE);

--Zad11
SELECT
  TO_CHAR(LAST_DAY(CURRENT_DATE), 'day d dd ddd mm w ww yyyy month')
FROM
  Studenci;

--Zad19
SELECT
  Nazwisko,
  Imiona,
  Data_urodzenia,
  TO_CHAR(Data_urodzenia,'DAY') AS "xyz"
FROM
  Studenci
WHERE
    TRIM(TO_CHAR(Data_urodzenia,'day'))IN ('SOBOTA','NIEDZIELA')
AND TRIM(TO_CHAR(Data_urodzenia,'MONTH'))IN ('LIPIEC','SIERPIEN')
AND MOD(EXTRACT(DAY FROM data_urodzenia),5)!=0; --pusty wyniki(?)
--Zad20
SELECT
  Nazwisko,
  Stanowisko,
  Data_zatr,
  Data_zwol,
  TRUNC(MONTHS_BETWEEN(SYSDATE,data_zatr)/12)||' lat '||
  (TRUNC(MONTHS_BETWEEN(SYSDATE,data_zatr)/12)-
  TRUNC(MONTHS_BETWEEN(SYSDATE,data_zatr)/12)*12)
FROM
  Pracownicy
WHERE
  Data_zwol IS NULL OR data_zwol >= SYSDATE;

--Zad22
SELECT * FROM Studenci
WHERE data_urodzenia BETWEEN TO_DATE('13-12-1995','dd-mm-yyyy') AND TO_DATE('28-11-1998','dd-mm-yyyy')
AND TRIM(TO_CHAR(Data_urodzenia,'day'))LIKE ('SOBOTA')
AND TO_CHAR(Data_urodzenia,'W') = 1;

--Zad23
SELECT Imiona, Nazwisko FROM studenci
WHERE REGEXP_COUNT(imiona, '[[:alpha:]]') =5
AND regexp_like(nazwisko, '^(Ko)[[:alpha:]]{0,}(ski)$');

--Zad24
SELECT adres,
REGEXP_REPLACE(REGEXP_REPLACE(adres,'[[:alpha:]]{3,}','Alpha'),'[[:digit:]]{1,}','Digit')
FROM studenci;

--Zad25
SELECT adres FROM studenci
WHERE
  regexp_like(adres, '^(al.\s)(P|B|T|W).{0,} 68');


SELECT ROWNUM, id_gatunku, waga FROM rejestry WHERE id_gatunku IS NOT NULL
AND ROWNUM <= 10
ORDER BY 3 DESC;
--zad28
SELECT EXTRACT(YEAR FROM czas), i_gatunku, waga,
MIN(waga) KEEP (DENSE_RANK FIRST ORDER BY waga)
over (PARTITION BY id_gatunku) xx,
MIN(waga) KEEP (DENSE_RANK FIRST ORDER BY waga)
over (PARTITION BY id_gatunku) yy
FROM rejestry WHERE id_gatunku IS NOT NULL
ORDER BY 1;