计算按b列分组的a列的sql百分比

我的数据如下：

名称|颜色 如何编写SQL来生成以下内容

名称|颜色|百分比 下面是我在microsoft access SQL中尝试的代码

select name, color, (count(color)*100.0/count(*)) as 'perc'
from mytable
group by name, color;

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你需要得到每种颜色的总数才能得到百分比。这需要加入另一个值。我认为以下几点将在Access中起作用：

select nc.name, nc.color, nc.cnt * 100 / n.cnt & '%'
from (select name, color, count(*) as cnt
      from mytable as t 
      group by name, color
     ) as nc inner join
     (select name, count(*) as cnt
      from mytable as t
      group by name
     ) as n
     on nc.name = n.name;

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嘿，谢谢戈登，我试过谷歌搜索，但我觉得这个问题比我找到的答案要复杂一点。access如何知道“nc”和“n”是什么？@barker这些是别名，可以将它们分配给表或子查询，它们有助于提高可读性，并使引用同一个表时能够区分。它们在子查询的

）

之后分配。

select name, color, (count(color)*100.0/count(*)) as 'perc'
from mytable
group by name, color;

select nc.name, nc.color, nc.cnt * 100 / n.cnt & '%'
from (select name, color, count(*) as cnt
      from mytable as t 
      group by name, color
     ) as nc inner join
     (select name, count(*) as cnt
      from mytable as t
      group by name
     ) as n
     on nc.name = n.name;