alter session set nls_date_format='yyyy/mm/dd hh24:mi:ss';
select sysdate from dual;
SELECT NOW();
SELECT CURRENT_TIMESTAMP();
SELECT CURRENT_TIMESTAMP;
select clock_timestamp();
select GETDATE();
select sysdatetime();
alter session set nls_date_format='yyyy/mm/dd hh24:mi:ss';
select sysdate from dual;
SELECT NOW();
SELECT CURRENT_TIMESTAMP();
SELECT CURRENT_TIMESTAMP;
select clock_timestamp();
select GETDATE();
select sysdatetime();