PHP 数据库操作，怎么以日期取出每天出现的不同ip数量。

Question

我有张表，如下图，我想以datetime排序，获得每天出现过几个ip地址。
我用下面这段的话，只能取出总数，不是个数

    
    
    $data['num_ip'] = Db::name("visitors")->where($where)->field("count(ip) as count,datetime")->group("datetime")->select();

，

Answer 1

count(distinct ip)

Answer 2

SELECT COUNT(DISTINCT `ip`), `datetime` 
FROM [TABLE_NAME]
GROUP BY `datetime` 
ORDER BY `datetime` ASC;

Answer 3

这得嵌套查询了吧，第一层按日期，IP去重，第二层再像你现在这样

select count(ip) as count,datetime from 
(
    select ip,datetime from table_name group by ip,datetime
)as a 
group by datetime

Answer 4

count group by 或 count(distinct)