mysql avg(min())可以吗?
显然avg(min())给了我一个错误,所以我尝试了这段代码,但它给了我错误的数字。有什么想法吗 谢谢mysql avg(min())可以吗?,mysql,Mysql,显然avg(min())给了我一个错误,所以我尝试了这段代码,但它给了我错误的数字。有什么想法吗 谢谢 select out_year as "Year", avg(dwell_time) as "Average", avg(av.dw_min) as "Minimum", avg(av.dw_max) as "Maximum" from (select min(dwell_time) as dw_min, max(dwell_time) as dw_ma
select
out_year as "Year",
avg(dwell_time) as "Average",
avg(av.dw_min) as "Minimum",
avg(av.dw_max) as "Maximum"
from
(select min(dwell_time) as dw_min, max(dwell_time) as dw_max
from eq_dwell) av,
eq_dwell ed
where
inv_status = "Offdock"
group by out_year
你能给我们展示一下它给你带来的和你期望得到的吗?你的内部选择只会返回一行。那你怎么能取平均数呢?我认为您需要将
year
添加到内部选择中,然后按年份对内部选择进行分组。没关系,我进行了计算,发现avg(1,2,3,4)与avg(avg(1,2)+avg(3,4))不同,所以这样做没有用。谢谢你的评论。