我需要检索今天和过去几天的数据,并在mysql中计算平均值。
我的查询是
select aqi_id,
r_aqi_id,
avg(aqi_value),
added_date
from
sfr_aqi
order by
ra.added_date desc
limit 0,3
请建议我更好的方法。
在最后三天尝试这个NOW() - INTERVAL 3 DAY
select aqi_id,
r_aqi_id,
avg(aqi_value),
added_date
from
sfr_aqi
where ra.added_date >= NOW() - INTERVAL 3 DAY
group by aqi_id /* you can also use group by ra.added_date */
order by
ra.added_date desc
limit 0,3