平均值 - Mysql

Question

我有一个SQL查询，如下所示：

SELECT COUNT(*)
FROM event_db.event_log el, event_db.event_type et
WHERE et.event_type_id = el.event_type_id AND et.name in ('kpi_stats_dumped') AND el.timestamp > str_to_date('2016,12,12','%Y,%m,%d') AND el.timestamp < str_to_date('2017,12,12','%Y,%m,%d')
GROUP BY et.name, date_format(el.timestamp, '%d-%m-%Y')
ORDER BY et.name, el.timestamp

将返回结果如下：

1440
1441
1546
1234
1235
33
224

我需要找到列出的值的平均值。（1021.85714286）

有人可以帮助我。

Answer 1

select avg(cnt) as average_count
from 
(
    SELECT COUNT(*) as cnt
    FROM event_db.event_log el
    JOIN event_db.event_type et ON et.event_type_id = el.event_type_id
    WHERE et.name in ('kpi_stats_dumped') 
    AND el.timestamp > str_to_date('2016,12,12','%Y,%m,%d') 
    AND el.timestamp < str_to_date('2017,12,12','%Y,%m,%d')
    GROUP BY et.name, date_format(el.timestamp, '%d-%m-%Y')
) tmp

Answer 2

我得到了答案，现在查询如下：

SELECT avg(cnt) from 
(SELECT count(*) as cnt
FROM  event_db.event_log el ,
      event_db.event_type et
WHERE et.event_type_id = el.event_type_id
      AND et.name IN ( 'kpi_stats_dumped' )
      AND el.timestamp > str_to_date('2016,12,12', '%Y,%m,%d')
      AND el.timestamp < str_to_date('2017,12,12', '%Y,%m,%d')
GROUP BY et.name , date_format(el.timestamp, '%d-%m-%Y')
ORDER BY et.name, el.timestamp) tmp