按某一列分组并筛选时间最新的一条记录
方法一:
-- 方法1 select a.* from table a where not exists(select 1 from table b where b.id_no=a.id_no and b.crt_time>a.crt_time)
方法二:子查询
-- 方法2 select a.* from table a inner join (select id_no, max(crt_time) max_time from table group by id_no) b on a.id_no=b.id_no and a.crt_time=b.max_time