Here I'm just doing the difference between today, and a CREATED_DATE
DATE
field in a table, which obviously is a date in the past:
SELECT
((FLOOR(ABS(MONTHS_BETWEEN(CREATED_DATE, SYSDATE))) / 12) * 12) || ' months, ' AS MONTHS,
-- we take total days - years(as days) - months(as days) to get remaining days
FLOOR((SYSDATE - CREATED_DATE) - -- total days
(FLOOR((SYSDATE - CREATED_DATE)/365)*12)*(365/12) - -- years, as days
-- this is total months - years (as months), to get number of months,
-- then multiplied by 30.416667 to get months as days (and remove it from total days)
FLOOR(((SYSDATE - CREATED_DATE)/365)*12 - (FLOOR((SYSDATE - CREATED_DATE)/365)*12)) * (365/12))
|| ' days ' AS DAYS
FROM MyTable
I use (365/12), or 30.416667, as my conversion factor because I'm using total days and removing years and months (as days) to get the remainder number of days. It was good enough for my purposes, anyway.