select a.*  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=  '';--加上where条件是查询一条，不加是查询多条

SELECT * FROM table  WHERE  (id,createtime)  IN (SELECT id,MAX(createtime)  createtime  FROM  table  GROUP  BY  id);--获取时间最新的多条数据

SELECT * FROM table where a.id=''  and createtime=(SELECT MAX(createtime) FROM table where a.id='');--获取一条时间最新的数据