Question

我有一张包含以下内容的表格：

| Country       | Username       |
+---------------+----------------+
| US            | John           |
| IT            | Pedro          |
| US            | Bob            |
| FR            | Jill           |
| 192.168.1.2   | Roupraht       |
| 192.168.1.20  | Antonio        |
+---------------+----------------+

我想计算每个国家/地区的用户，而使用IP地址而不是国家/地区的用户应计为＆＃34;未知＆＃34;;

我设法编写了以下SQL查询：

select country, count(*) as total from users group by country;

我得到了以下结果：

+-----------------+-------+
| country         | total |
+-----------------+-------+
| 192.168.1.2     |     1 |
| 192.168.1.20    |     1 |
| US              |     2 |
| IT              |     1 |
| FR              |     1 |
+-----------------+-------+

如何将所有IP地址统计为＆＃34;未知＆＃34; ？
我的目标是得到这样的表：

+-----------------+-------+
| country         | total |
+-----------------+-------+
| Unknown         |     2 |
| US              |     2 |
| IT              |     1 |
| FR              |     1 |
+-----------------+-------+

Answer 1

如果有IP地址被视为Unknown，您可以执行以下操作

select 
country,count(*) as tot 
from users 
where inet_aton(country) is null 
group by country 
union all 
select 
'Unknown',count(*) as tot 
from users 
where inet_aton(country) is not null;

https://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_inet-aton

Answer 2

你可以使用带有if语句的mysql LIKE语句：

select if(country LIKE '%.%.%.%', 'unknown', country), count(*) as total from users group by country;

Answer 3

你可以用这个

set @unknown = (select country from table where country LIKE '%.%.%.%');

为所有IP地址设置变量'unknown'

分组并过滤mysql结果

3 个答案: