TRUNC[ATE] (datetime)
Purpose
This function returns a date and/or a timestamp, which is trimmed following the format definition. Accordingly, TRUNC(datetime) behaves in the same way as ROUND (datetime), with the exception that TRUNC rounds-down.
Syntax
trunc (datetime)::=
Usage Notes
- The following elements can be used as format:
- A similar functionality provides the PostgreSQL compatible function DATE_TRUNC.
- If a format is not specified, the value is truncated to days.
- For data type TIMESTAMP WITH LOCAL TIME ZONE this function is calculated within the session time zone.
CC, SCC | Century |
YYYY, SYYY, YEAR, SYEAR, YYY, YY, Y | Year |
IYYY, IYY, IY, I | Year in accordance with international standard, ISO 8601 |
Q | Quarter |
MONTH, MON, MM, RM | Month |
WW | Same day of the week as the first day of the year |
IW | Same day of the week as the first day of the ISO year |
W | Same day of the week as the first day of the month |
DDD, DD, J | Day |
DAY, DY, D | Starting day of the week. The first day of a week is defined by the parameter NLS_FIRST_DAY_OF_WEEK (refer to ALTER SESSION and ALTER SYSTEM). |
HH, HH24, HH12 | Hour |
MI | Minute |
SS | Seconds |