具有重复电子邮件ID的不同行的计数

Question

如何在SQL中获取具有重复电子邮件ID的不同行的计数？

ID   NAME   EMAIL 
1    John   asd@asd.com 
2    Sam    asd@asd.com 
4    Bob    bob@asd.com 
5    Tom    asd@asd.com 
6    Rob    bob@asd.com
7    Tic    tic@asd.com
8    Dad    dad@asd.com

查询应该返回2。 asd@asd.com和bob@asd.com是重复的

SELECT 
 COUNT(*)  
FROM Users
GROUP BY EMail 
HAVING ( COUNT(EMAIL) > 1 )    

此查询返回一些奇怪的结果。 感谢

Answer 1

行数：

select sum(cnt)
from (select count(*) as cnt
    from Users
    group by email
    having count(*) > 1) T

电子邮件数量：

select count(*)
from (select count(*) as cnt
    from Users
    group by email
    having count(*) > 1) T

两者都是：

select count(*) as COUNT_EMAIL sum(cnt) as COUNT_ROWS
from (select count(*) as cnt
    from Users
    group by email
    having count(*) > 1) T

上面应该适用于SQL Server和Oracle。