sql语句操作数据库重复数据

1.示例表

Create Table TableA
(
    id int,
    NameA varchar(10)
)

2.判断NameA列是否有重复数据

select NameA from TableA group by NameA having count(1)>1

3.删除NameA列重复的数据，只留一条。

alter table TableA add autoID int identity
delete TableA where autoID not in (select min(autoID) as autoID from TableA group by NameA)
alter table TableA drop column autoID

先增加一个自增列，然后删除不是最小的，删除自增列

 

来源：http://www.it118.org/specials/c9fba99e-4401-49cf-8256-ac3c1a34c0d9/35402864-969a-4e7f-b50e-5bc30d4c07d4.htm