擅长:python、mysql、java
<p>在SQL中,您可以通过跟踪输入和输出,然后进行累积求和来处理此问题:</p>
<pre><code>with io as (
select entry_time as dt, 1 as inc
from t
union all
select exit_time + interval 1 day as dt, -1
from t
)
select dt, sum(inc) as change_on_day,
sum(sum(inc)) over (order by dt) as active_on_day
from io
group by dt
order by active_on_day desc
limit 1;
</code></pre>
<p><a href="https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=a0fa20f93e8ea9688eb925d345fd7987" rel="nofollow noreferrer">Here</a>是一个db<&燃气轮机;小提琴</p>