acquiring first data sorting oracle

A: according to a sort field (time, total number, etc.), first obtain

SELECT A. *   the FROM (
      SELECT  *   from (
             SELECT T. * , ROW_NUMBER () over (Partition by t.id
 Order  by t.createtime desc ) RN    from  Table T 
) C   WHERE RN =  . 1 ) A
   WHERE a.id =   ' 001 ' ; - add the proviso that where a query, the query without a plurality of

 

Two: If it is time to get the latest piece of data

The SELECT  *  the FROM  Table   the WHERE   (ID, CreateTime)   the IN ( the SELECT ID, MAX (CreateTime) CreateTime   the FROM   Table   the GROUP   BY   ID); - obtaining a plurality of data of the latest time 

the SELECT  *  the FROM  Table  WHERE a.id = ' 018 '   and CreateTime = ( the SELECT  MAX (CreateTime) the FROM  Table  WHERE a.id = ' 018 ' ); - obtaining a time-date data