我有以下问题:
select count(*) as headct
, case
when year(DOB) <= 1945 then 'Traditionalist'
when year(DOB) >= 1946 and year(DOB) < 1965 then 'Baby Boomer'
when year(DOB) >= 1965 and year(DOB) < 1981 then 'Gen X'
when year(DOB) >= 1981 then 'Gen Y'
end as generation
from ret_active
group by Generation with rollup;
它返回这个表:
headct generation
--------------------------
1820 Baby Boomer
2208 Gen X
883 Gen Y
17 Traditionalist
4928 null
如何添加另一列来显示每个类别的总数百分比?换句话说,我怎样才能得到以下结果:
headct generation % of Total
-------------------------------------
1820 Baby Boomer 37%
2208 Gen Xm 45%
883 Gen Y 18%
17 Traditionalist 0%
4928 null 100%
谢谢!
最佳答案
select count(*) as headct
, case
when year(DOB) <= 1945 then 'Traditionalist'
when year(DOB) >= 1946 and year(DOB) < 1965 then 'Baby Boomer'
when year(DOB) >= 1965 and year(DOB) < 1981 then 'Gen X'
when year(DOB) >= 1981 then 'Gen Y'
end as generation
, concat(round(count(*)/
(select count(*) from ret_active)*100,0),'%') as '% of Total'
from ret_active
group by Generation with rollup
关于mysql - 如何计算MySQL中的总数百分比,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22718691/