如果需要与max\u daye相关的行，可以使用join和max time1的子查询

select   m.p_id, m.aaa, m.bbb, m.ccc 
from mytable m
inner join (
  SELECT p_id,  max(time1) max_date 
  FROM   mytable
  group by p_id 
) t on t.max_date =  m.time1  and t.p_id = m.p_id

或者，如果您只需要每个p\U id的最大值，您可以使用

select   m.p_id, max(m.aaa), max(m.bbb), max(m.ccc )
from mytable m
group by m-p_id

可以使用相关子查询：

select t.*
from table t
where time1 = (select max(t1.time1) from table t1 where t1.p_id = t.p_id);

可以使用相关子查询为每个不同id的每一列获取“最新”的非空值。

SELECT t1.p_id,
       (SELECT t2.aaa
               FROM elbat t2
               WHERE t2.p_id = t1.p_id
                     AND t2.aaa IS NOT NULL
               ORDER BY t2.time1 DESC
               LIMIT 1) aaa,
       ...
       (SELECT t2.ccc
               FROM elbat t2
               WHERE t2.p_id = t1.p_id
                     AND t2.ccc IS NOT NULL
               ORDER BY t2.time1 DESC
               LIMIT 1) ccc,
       FROM (SELECT DISTINCT
                    p_id
                    FROM elbat) t1;