toad经常与oracle一起使用，所以我将使用oracle语法。您可以适应其他数据库。关键是从中提取日期 start_date .

select t.*
from (select t.*,
             row_number() over (partition by trunc(start_date) order by start_date desc) as seqnum
      from t
     ) t
where seqnum = 1;