Примеры команд SQL в рамках урока #24

-- Функции SQL для даты и времени (SYSDATE, TO_DATE, LAST_DAY, ADD_MONTHS, EXTRACT, TRUNC)
-- https://youtu.be/_6XWUJ2zf8Y

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-- Примеры команд SQL в рамках урока #24


SELECT SYSDATE FROM dual;
SELECT TO_CHAR(SYSDATE, 'YYYY/MM/DD HH24:MI:SS') FROM dual;

SELECT TO_DATE('29.12.2020', 'dd.mm.yyyy') FROM dual;
SELECT TO_DATE('29/12/2020', 'dd/mm/yyyy') FROM dual;
SELECT TO_DATE('2020/12/29', ' yyyy/mm/dd') FROM dual;
SELECT TO_DATE('29.12.2020 15:45:30', 'DD.MM.YYYY HH24:MI:SS') FROM dual;

SELECT LAST_DAY(TO_DATE('15.12.2020', 'dd.mm.yyyy')) FROM dual;

SELECT ADD_MONTHS(TO_DATE('29.12.2020', 'dd.mm.yyyy'), 1) FROM dual;
SELECT ADD_MONTHS(TO_DATE('29.12.2020', 'dd.mm.yyyy'), -1) FROM dual;

SELECT EXTRACT(YEAR FROM to_date('29.12.2020', 'dd.mm.yyyy')) FROM dual;
SELECT EXTRACT(MONTH FROM to_date('29.12.2020', 'dd.mm.yyyy')) FROM dual;
SELECT EXTRACT(DAY FROM to_date('29.12.2020', 'dd.mm.yyyy')) FROM dual;

SELECT SYSDATE FROM dual;
SELECT TRUNC(SYSDATE, 'YEAR') FROM dual;
SELECT TRUNC(SYSDATE, 'Q') FROM dual;
SELECT TRUNC(SYSDATE, 'MONTH') FROM dual;
SELECT TRUNC(SYSDATE, 'IW') FROM dual;