查找唯一的列对

Question

假设我的表看起来像这样：

1. user 1.2.3.4
2. user 1.2.3.4
3. user 2.3.4.5
4. user 2.3.4.5
5. user 1.2.3.5
6. anotheruser 1.2.3.6
7. anotheruser 1.2.3.4

我想获得所有带用户名的ips列表。查询可能如下所示：

select username, ip from client_logs where ip is unique

我想要这样的输出：

user 1.2.3.4
user 2.3.4.5
user 1.2.3.5
anotheruser 1.2.3.6
anotheruser 1.2.3.4

我已经尝试通过select distinct来做到这一点，但我只有ips或ip-user。我试过的查询是：

SELECT DISTINCT ip, username
FROM client_logs
ORDER BY username

Answer 1

USE GROUP BY

SQL Fiddle Demo

SELECT username, ip
FROM client_logs
GROUP BY username, ip
ORDER BY username, ip

修改

我也尝试了你的第一个解决方案并且正常工作

Only distinct DEMO

SELECT distinct username, ip
FROM client_logs
ORDER BY username, ip

Answer 2

我通过以下查询解决了这个问题：

SELECT username, ip
FROM client_logs
GROUP BY ip
ORDER BY username, ip