SQLServer获取重复数据的方法

SQL Server获取重复数据的方法
one获取重复数据值
select user _ name from users
group by user _ name
having(count(1)> 1)
two获取重复数据记录
select * from users where user _ name in
(
select user _ name from users
group by user _ name
having(count(1)> 1)
)