如果日期字段不重复可以这样
select * from tbtest where bb_date in (select max(bb_date) from tbtest group by convert(varchar(7),bb_date,120))
select * from tbtest where bb_date in (select max(bb_date) from tbtest group by convert(varchar(7),bb_date,120))
inner join (select max(bb_date) bb_date from test group by convert(varchar(7),bb_date,120) ) b on a.bb_date=b.bb_date