示例:test 表 a b c
1 5 abc
2 6 bcd
1 7 ade
2 8 adc
若取按a列分组后,b列最大,的所有列的记录：
result a b c
1 6 bcd
2 8 adc
可以使用如下语句：
select * from test where b in (select max(id) from test group by a)
适用于所有数据库：
select t1.a,t1.b,t1.c
from test t1
inner join
(seelct a,max(b) as b from test group by a) t2
on t1.a=t2.a and t1.b=t2.b
适用于所有数据库：
select a,b,c
from(
select a,b,c
,row_number()over(partition by a order by b desc) rn
from test
)
where rn=1