mysql 去除重复sql语句

[lovemy016]

根据emai字段去除重复，有个附加条件是另一个字段出现频率最高的数据保留，其他的删除
数据表中有
id email country
1 [e-mail] Japan
2 [e-mail] China
3 [e-mail] China
4 [e-mail] Japan
5 [e-mail] Chain
6 [e-mail] Chain
去除重复项的结果为

[e-mail] China
[e-mail] Japan
[e-mail] Chain

重复的email [e-mail] country ，China有3次，Japan有两次，左右保留的Chain

[rucypli]

select email,country
from tb
group by email,country

[wwwwb]

select * from (
SELECT email,country,count(*) as gs from [long] group by email,country) a
where not exists(select 1 from (SELECT email,country,count(*) as gs from [long] group by email,country) a1 where a.email=a1.email and a.gs<a1.gs)

[lovemy016]

自己解决了

[mysqldbd]

[Quote=引用 4 楼 lovemy016 的回复:]

自己解决了
[/Quote]

恭喜自力更生！

[ACMAIN_CHM]

select distinct email,country  
from 数据表

[lxq19851204]

Japan有两次,不是就只有1次的嘛