Oracleの時間関連アクション

ディレクトリのナビゲーション:
1.年間操作
2.月操作
3.週操作
4.日単位の操作
5.時操作
6.分割操作
7.秒操作
1、年間操作

SELECT add_months(SYSDATE, -12) FROM dual;  --       (1)
SELECT SYSDATE - INTERVAL '1' YEAR FROM DUAL; --       (2)
SELECT add_months(SYSDATE, 12) FROM dual;  --       (1)
SELECT SYSDATE + INTERVAL '1' YEAR FROM DUAL; --       (2)

2.月操作

SELECT add_months(SYSDATE, -1) FROM dual;  --        (1)
SELECT SYSDATE - INTERVAL '1' MONTH FROM dual;  --        (2)
SELECT add_months(SYSDATE, 1) FROM dual;   --        (1)
SELECT SYSDATE + INTERVAL '1' MONTH  FROM dual;   --        (2)

3.週操作

SELECT SYSDATE +7 FROM dual;  --       (1)
SELECT SYSDATE,SYSDATE + INTERVAL '7' DAY FROM dual;  --       (2)
SELECT SYSDATE -7 FROM dual;  --       (1)
SELECT SYSDATE,SYSDATE - INTERVAL '7' DAY FROM dual;  --         (2)

4.日単位の操作

SELECT SYSDATE FROM dual;  --      

SELECT SYSDATE - 1 FROM dual;  --      (1)
SELECT SYSDATE,SYSDATE - INTERVAL '1' DAY FROM dual;  --      (2)   
SELECT SYSDATE + 1 FROM dual;  --      (1)
SELECT SYSDATE + INTERVAL '1' DAY FROM dual;  --      (2)

5.時操作

SELECT SYSDATE - 1/24 FROM dual; --          (1)
SELECT SYSDATE - INTERVAL '1' HOUR FROM dual; --          (2)
SELECT SYSDATE + 1/24 FROM dual; --           (1)
SELECT SYSDATE,SYSDATE + INTERVAL '1' HOUR FROM dual; --           (2)

6.分割操作

SELECT SYSDATE - 1/24/60 FROM dual; --          (1)
SELECT SYSDATE - INTERVAL '1' MINUTE FROM dual; --          (2)
SELECT SYSDATE + 1/24/60 FROM dual; --          (1)
SELECT SYSDATE,SYSDATE + INTERVAL '1' MINUTE FROM dual; --          (2)

7.秒操作

SELECT SYSDATE - 1/24/60/60 FROM dual;  --         (1)
SELECT SYSDATE - INTERVAL '1' SECOND FROM dual;  --         (2)
SELECT SYSDATE + 1/24/60/60 FROM dual;  --         (1)
SELECT SYSDATE,SYSDATE + INTERVAL '1' SECOND FROM dual;  --         (2)