查符合的 ip
```
select distinct a.ip
from (
select a.ip, a.时间, count(b.时间) num
from table a,
table b
where a.ip = b.ip and b.时间 between date_sub(a.时间, interval 30 minute) and a.时间
group by a.ip, a.时间
having num > 20) a;
```
查符合的单号
```
select a.ip, a.时间, count(b.时间) num, group_concat(b.单号) ids
from myt_sales_order a,
myt_sales_order b
where a.ip = b.ip and b.时间 between date_sub(a.时间, interval 30 minute) and a.时间
group by a.ip, a.时间
having num > 4;
```