CREATE TABLE hard(
id int IDENTITY(1,1) primary key ,
aa varchar(50) ,
bb int ,
)
insert into hard values('a',9)
insert into hard values('a',7)
insert into hard values('a',8)
insert into hard values('a',6)
insert into hard values('b',2)
insert into hard values('b',3)
insert into hard values('b',4)
insert into hard values('c',1)
insert into hard values('c',8)
insert into hard values('c',2)
要求查询出每个品种值最大的前2项
查询结果如下
a 9
a 8
b 4
b 3
c 8
c 2
求大神SQL