问题
With this query: select sysdate from dual;
the result is: 27-09-2018 07:50:50 -- this UK time
with : Select dbtimezone from dual;
output: +10:00
I want the sysdate to be of the same timezone of dbtimezone
I was trying to do it with alter database set time_zone='AEST', but i'm bit confused if this is the right solution.
Any help most appreciated. Thanks.
回答1:
It is a common misunderstanding that DBTIMEZONE is the time zone for SYSDATE and SYSTIMESTAMP
SYSDATE and SYSTIMESTAMP are returned in time zone of the operating system on which the database server resides.
DBTIMEZONE is the (internal) time zone of TIMESTAMP WITH LOCAL TIME values. I don't know any practical use of it. Note, you cannot change DBTIMEZONE on your database if the database contains a table with a TIMESTAMP WITH LOCAL TIME ZONE column and the column contains data.
If you want current time at DBTIMEZONE run
select SYSTIMESTAMP AT TIME ZONE DBTIMEZONE
from dual;
CURRENT_TIMESTAMP AT TIME ZONE DBTIMEZONE is also working.
See also How to handle Day Light Saving in Oracle database
回答2:
SYSDATE returns the current date and time set for the operating system on which the database server resides.
CURRENT_DATE returns the current date in the session time zone.
show parameter nls_date_format
NAME TYPE VALUE
------------------------------ ----------- ------------------------
nls_date_format string dd-Mon-yyyy hh24:mi:ss
select sysdate, current_date, dbtimezone from dual;
SYSDATE CURRENT_DATE DBTIME
-------------------- -------------------- ------
27-Sep-2018 08:16:00 27-Sep-2018 08:16:00 +00:00
alter session set time_zone = '+08:00';
Session altered.
select sysdate, current_date, dbtimezone from dual;
SYSDATE CURRENT_DATE DBTIME
-------------------- -------------------- ------
27-Sep-2018 08:13:06 27-Sep-2018 15:13:06 +00:00
来源：https://stackoverflow.com/questions/52531137/sysdate-and-dbtimezone-different-in-oracle-database