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SQL code:
±íA
id name
1 aa
2 aa
3 aa
4 bb
5 cc
6 cc
7 ee
8 ff
9 ff


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id name
3 aa
4 bb
6 cc
7 ee
9 ff


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SQL code:
select max(ID)ID,
name
from tb group by name

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SQL code:
---²âÊÔÊý¾Ý---
if object_id('[A]') is not null drop table [A]
go
create table [A]([id] int,[name] varchar(2))
insert [A]
select 1,'aa' union all
select 2,'aa' union all
select 3,'aa' union all
select 4,'bb' union all
select 5,'cc' union all
select 6,'cc' union all
select 7,'ee' union all
select 8,'ff' union all
select 9,'ff'

---ɾ³ý---
delete a
from a t
where not exists(select 1 from a where name=t.name and id<t.id)

---²éѯ---
select * from [A]

---½á¹û---
id name
----------- ----
2 aa
3 aa
6 cc
9 ff

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delete from A where not exists ( select 1 from (select max(id) A_id,name&nbs