简单sql问题

[zhongdongzhe]

表名：student;
字段：id(主键，标识列);XingM(姓名);KeM(科目);ChengJ(成绩)
表中记录：
id XingM KeM ChengJ
1 张三 语文 80
2 张三 数学 90
3 张三 英语 70
4 张三 语文 80
5 张三 数学 90

问题1：要求用一条SQL语句显示出所有后三列重复的行；(最好能把字段id列也显示)
问题2：删除重复行，只保留一行记录。（类似第4、5行需要删掉）

[txlicenhe]

1:
Select a.* from student a
join (select XingM,KeM,ChengJ from student group by XingM,KeM,ChengJ having count(*) > 1) b on a.XingM = b.XingM and a.KeM = b.KeM and a.ChengJ = b.ChengJ
2:
Delete student a where id <>
(select Min(id) from student where XingM = a.XingM and KeM = a.KeM and ChengJ = a.ChengJ)

[friendliu]

1.select XingM,KeM,ChengJ from a
group by XingM,KeM,ChengJ
having count(*)>1

[friendliu]

1.select XingM,KeM,ChengJ from student
group by XingM,KeM,ChengJ
having count(*)>1

[friendliu]

2.
delete from student a where id<>(select min(id) from student b where b.Xingm=a.Xingm and b.Kem=a.Kem and b.Chengj=a.Chengj)
go

[dafu71]

1.select XingM,KeM,ChengJ from student
group by XingM,KeM,ChengJ
having count(*)>1
2 delete from student where
id not in (select min(id) from student group by XingM,KeM,ChengJ)

[DigJim]

select distinct XingM,KeM,ChengJ from student

[aierong]

create table ai( id int, XingM varchar(100), KeM varchar(100), ChengJ int)
insert into ai select 1, '张三' , '语文', 80
insert into ai select 2, '张三' , '数学' , 90
insert into ai select 3, '张三' , '英语' , 70
insert into ai select 4, '张三' , '语文' , 80
insert into ai select 5, '张三', '数学' , 90
问题1：要求用一条SQL语句显示出所有后三列重复的行；(最好能把字段id列也显示)
问题2：删除重复行，只保留一行记录。（类似第4、5行需要删掉）

1.

select min(id) id,XingM ,KeM ,ChengJ
from ai
group by XingM ,KeM ,ChengJ
order by 1

2.
delete from ai
where id not in (
select min(id)
from ai
group by XingM ,KeM ,ChengJ)