CURRENT_TIMESTAMP y LOCALTIMESTAMP

CURRENT_TIMESTAMP

Syntax

Purpose

CURRENT_TIMESTAMP returns the current date and time in the session time zone, in a value of datatype TIMESTAMP WITH TIME ZONE. The time zone offset reflects the current local time of the SQL session. If you omit precision, then the default is 6. The difference between this function and LOCALTIMESTAMP is that CURRENT_TIMESTAMP returns a TIMESTAMP WITH TIME ZONE value while LOCALTIMESTAMP returns a TIMESTAMP value.

In the optional argument, precision specifies the fractional second precision of the time value returned.



Examples

The following example illustrates that CURRENT_TIMESTAMP is sensitive to the session time zone:

ALTER SESSION SET TIME_ZONE = '-5:0';
ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MON-YYYY HH24:MI:SS';
SELECT SESSIONTIMEZONE, CURRENT_TIMESTAMP FROM DUAL;

SESSIONTIMEZONE CURRENT_TIMESTAMP
--------------- ---------------------------------------------------
-05:00          04-APR-00 01.17.56.917550 PM -05:00

ALTER SESSION SET TIME_ZONE = '-8:0';
SELECT SESSIONTIMEZONE, CURRENT_TIMESTAMP FROM DUAL;

SESSIONTIMEZONE CURRENT_TIMESTAMP
--------------- ----------------------------------------------------
-08:00          04-APR-00 10.18.21.366065 AM -08:00

LOCALTIMESTAMP

Syntax

Purpose

LOCALTIMESTAMP returns the current date and time in the session time zone in a value of datatype TIMESTAMP. The difference between this function and CURRENT_TIMESTAMP is that LOCALTIMESTAMP returns a TIMESTAMP value while CURRENT_TIMESTAMP returns a TIMESTAMP WITH TIME ZONE value.
The optional argument timestamp_precision specifies the fractional second precision of the time value returned.

Examples

This example illustrates the difference between LOCALTIMESTAMP and CURRENT_TIMESTAMP:

ALTER SESSION SET TIME_ZONE = '-5:00';
SELECT CURRENT_TIMESTAMP, LOCALTIMESTAMP FROM DUAL;

CURRENT_TIMESTAMP                    LOCALTIMESTAMP
-------------------------------------------------------------------
04-APR-00 01.27.18.999220 PM -05:00  04-APR-00 01.27.19 PM

ALTER SESSION SET TIME_ZONE = '-8:00';
SELECT CURRENT_TIMESTAMP, LOCALTIMESTAMP FROM DUAL;

CURRENT_TIMESTAMP                    LOCALTIMESTAMP
-----------------------------------  ------------------------------
04-APR-00 10.27.45.132474 AM -08:00  04-APR-00 10.27.451 AM

Fuenrtes: http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions037.htm#i999217
http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions079.htm#i999873