Question

所以我有一个CASE声明，我已经分组了。但是，我还试图计算每个Grouped CASE结果的总数百分比。当我运行下面的命令时，它会给出

Region         Number  Percentage
West Coast     11675   0
Not West Coast 104620  0

我不明白为什么＆＃39;百分比＆＃39;来自＆＃39; 0＆＃39;。

这是代码，问题行＆＃39;标记。

With [Summed Region] AS
(

SELECT 
    [State Province],

    CASE [State Province]
    WHEN 'Oregon' THEN 'West Coast'
    WHEN 'Washington' THEN 'West Coast'
    WHEN 'California' THEN 'West Coast'
    ELSE 'Not West Coast'
    END AS 'Region'

FROM 
  [WideWorldImportersDW].[Dimension].[City]
)

SELECT 
    Region,
    count(Region) AS Number,
    ---THE PROBLEM LINE IS BELOW THIS---
    count(region)/(select count(*) FROM [WideWorldImportersDW].[Dimension].
    [City]) AS Percentage


FROM 
    [Summed Region]

GROUP BY
    Region

该线的问题是什么？如果我分开两个部分，每个都返回正确的数字。但是当我把一个人分开时，我得到了＆＃39; 0＆＃39;。

谢谢！

Answer 1

它被称为整数除法。所以在某处添加一个小数：

SELECT Region, count(Region) AS Number,
       count(region) * 1.0 / (select count(*) FROM [WideWorldImportersDW].[Dimension].[City]) AS Percentage
FROM [Summed Region]
GROUP BY Region;

您也不需要子查询，因此请使用窗口函数：

SELECT Region, count(*) AS Number,
       count(*) * 1.0 / sum(count(*)) over () AS Percentage
FROM [Summed Region]
GROUP BY Region;

使用Grouped Case语句计算总计百分比

1 个答案: