oracle DBTIMEZONEʱÇøµ÷Õû

select dbtimezone from dual ;  --²é¿´Êý¾Ý¿âʱÇø
select sessiontimezone from dual ;  --²é¿´»á»°Ê±Çø
1.select u.name || '.' || o.name || '.' || c.name TSLTZcolumn
       from sys.obj$ o, sys.col$ c, sys.user$ u
         where c.type# = 231
                    and o.obj# = c.obj#
                    and u.user# = o.owner#;
  Ö´Ðд˾䣬Èç¹ûÄܲéѯµ½Êý¾Ý½øÐеÚ2²½²Ù×÷£¬·ñÔòתµ½3
2.Ö´ÐÐÏÂÁÐÓï¾ä
  --´´½¨Ò»¸öÁÙʱ±í
  create table ttt(
     order_id number ,
     oeder_Date date
  );
  --µ¼ÈëÊý¾Ý
  insert into ttt(order_id,oeder_date) select order_id,order_date from oe.orders
  --ÐÞ¸Äoe.orders±í
  alter table oe.orders drop column order_date
  alter table oe.orders add order_date date
  --½«ÁÙʱ±íÖеÄÊý¾Ý»Ö¸´µ½oe.orders
  update oe.orders a set order_date = (select oeder_Date from ttt b where a.order_ID = b.order_id);
  --ɾ³ýÁÙʱ±í
  drop table ttt
3.ÐÞ¸Ä DBTIMEZONE
  alter database set time_zone='+08:00';
4.²é¿´DBTIMEZONE
  select DBTIMEZONE from dual ;