通过 http_user_agent 分组聚合，然后查询出各个代理的请求、以及返回客户端流量的和，由于单位是byte，运算转为MB并保留两位小数；再使用case when为status分层，分为2xx、3xx、4xx、5xx以及各层所占的比例。 使用表格展示，可以较为直观的看到这些数据及含义

* |
select
  http_user_agent as "用户代理",
  count(*) as pv,
  round(sum(request_length) / 1024.0 / 1024, 2) as "请求报文流量(MB)",
  round(sum(body_bytes_sent) / 1024.0 / 1024, 2) as "返回客户端流量(MB)",
  round(
    sum(
      case
        when status >= 200
        and status < 300 then 1
        else 0
      end
    ) * 100.0 / count(1),
    6
  ) as "2xx比例(%)",
  round(
    sum(
      case
        when status >= 300
        and status < 400 then 1
        else 0
      end
    ) * 100.0 / count(1),
    6
  ) as "3xx比例(%)",
  round(
    sum(
      case
        when status >= 400
        and status < 500 then 1
        else 0
      end
    ) * 100.0 / count(1),
    6
  ) as "4xx比例(%)",
  round(
    sum(
      case
        when status >= 500
        and status < 600 then 1
        else 0
      end
    ) * 100.0 / count(1),
    6
  ) as "5xx比例(%)"
group by
  "用户代理"
order by
  pv desc
limit
  100

SQL查询结果样例：