Oracle 中 DATEADD() 的等效函数

Question

I have to get a date that is 6 months from the system date in Oracle.
And I have to get it by running an open-query from SQL. DATEADD(MONTH,-6, GETDATE()) function serves the purpose in SQL.

Does the function DATEADD(MONTH,-6, GETDATE()) in SQL have an equivalent function in Oracle?

Answer 1

Method1: ADD_MONTHS

ADD_MONTHS(SYSDATE, -6)

Method 2: Interval

SYSDATE - interval '6' month

Note: if you want to do the operations from start of the current month always, TRUNC(SYSDATE,'MONTH') would give that. And it expects a Date datatype as input.

Answer 2

Not my answer :

I wasn't too happy with the answers above and some additional searching yielded this :

SELECT SYSDATE AS current_date,

       SYSDATE + 1 AS plus_1_day,

       SYSDATE + 1/24 AS plus_1_hours,

       SYSDATE + 1/24/60 AS plus_1_minutes,

       SYSDATE + 1/24/60/60 AS plus_1_seconds

FROM   dual;

which I found very helpful. From http://sqlbisam.blogspot.com/2014/01/add-date-interval-to-date-or-dateadd.html

Answer 3

等效将是

ADD_MONTHS( SYSDATE, -6 )

Answer 4

--ORACLE SQL EXAMPLE
SELECT
SYSDATE
,TO_DATE(SUBSTR(LAST_DAY(ADD_MONTHS(SYSDATE, -1)),1,10),'YYYY-MM-DD')
FROM DUAL