oracle开窗函数：先分组，再按时间排序取第一条

select  t.*  
   from (select a.*, row_number() over(partition by 需要分组的字段 order by 更新时间 desc) rw  
           from 表 a) t  
  where t.rw = 1  

实例：

select  t.*  
   from (select a.orgid,a.createdate, row_number() over(partition by orgid order by createdate desc) rw  
           from sec_per_complainlist a where a.yearmonth = '2018-01'
           and a.status in ('4', '5', '6', '7') /**状态为最终**/) t  
  where t.rw = 1