substr()截取字符串信息

select t.createtime,SUBSTR(t.createtime, 0, 10),
SUBSTR(t.createtime, 0, 13),
SUBSTR(t.createtime, 0, 16) ,SUBSTR(t.createtime, 0, 19)
from OA_EDDOCUMENT t where 1=1

select to_char(to_date(SUBSTR(t.createtime, 0, 16),‘yyyy-MM-dd HH24:mi’), ‘yyyy-MM-dd HH24:mi’) as CREATETIME
from OA_EDDOCUMENT t where 1=1