按月划分的类别份额百分比，而非累计

Question

我有一个数据，要计算类别的百分比份额（“文本”列），但是我想从计算中排除空白，并要按比例计算“月份”（文​​本列）

我的查询：

SELECT Category, Count(Category) AS CountOfCategory, Count([Category])/DCount("*","[Tablename]") AS MyPercent
FROM [Tablename]
GROUP BY Category;

查询的当前示例结果如下所示。

我的桌子看起来像这样

| Month Text | Category |  
|------------|----------|  
| Dec'18     | A        |  
| Nov'18     | A        |  
| Dec'18     | A        |  
| Nov'18     | C        |  
| Dec'18     | A        |  
| Nov'18     | C        |  
| Dec'18     | B        |  
| Nov'18     | C        |  

请帮助。

Answer 1

您的查询与您的数据示例不匹配，但我想此查询应该有帮助：

SELECT a.[Month Text], a.Category, Count(a.Category),
Count(a.Category)/
    (
    SELECT Count(b.Category)
    FROM yourtablename AS b
    WHERE b.[Month Text] = a.[Month Text]
    )
FROM yourtablename AS a
WHERE a.Category Is Not Null 
AND a.Category<>""
GROUP BY a.[Month Text], a.Category;