在事实表中确定百分比

Question

我是编程新手，找不到答案。

我有以下尺寸（表）和事实表：

• 客户： CustomerId ， HomeRegion
• 地区： RegionId ， RegionName
• MyTime： id ， MyHour
• 事实表： CustomerId ， RegionId ， TimeId ， FactId

我必须具有以下报告： HomeRegion ， Hour ， RegionName ， UserPercentage 。

如示例中所示，上午9点，只有3.67％的家庭区域是A的人迁移到B。

我应该创建一个类似的。

问题是获取ig UserPercentage。 这是我到目前为止所做的代码。

SELECT c.HomeRegion, mt.myhour as Time, r.RegionName as CurrentRegion,
(SELECT COUNT(*)
        /*number of users who move from their home 
        region to CurrentRegion at specific time*/
)/COUNT(c.CustomerId)*100 as UserPercentage
FROM dbo.FactTable ft 
inner join dbo.Customer c
    ON ft.CustomerId = c.CustomerId
inner join dbo.myTime mt
    ON ft.TimeId = mt.ID
inner join dbo.Regions r
    ON ft.RegionId = r.RegionId
WHERE mt.myhour = '09'
GROUP BY c.HomeRegion, mt.myhour, r.RegionName
ORDER BY c.HomeRegion, r.RegionName

Answer 1

在您的评论区域尝试类似的方法。

SELECT (TMP1.Count*100)/COUNT(TMP2.CustomerId) AS 'Percentage' 
FROM 
(
SELECT COUNT(*) AS 'Count' 
FROM dbo.FactTable ft 
inner join dbo.Customer c ON ft.CustomerId = c.CustomerId 
inner join dbo.Regions r ON ft.RegionId = r.RegionId 
WHERE 
r.RegionName IN ('A','B','C','D','E') AND 
c.HomeRegion IN ('A','B','C','D','E') 
) AS 'TMP1', dbo.Customer AS 'TMP2'

Answer 2

使用分析功能
*无需选择或按myHour常数分组
*假设一位客户应一次位于1个区域中（如果不是，则很难选择）

select HomeRegion, CurrentRegion, 
count(*) / count(*) over () as overall_share,
count(*) / count(*) over (partition by HomeRegion) as homeregion_share, 
    from
    (SELECT c.HomeRegion, r.RegionName as CurrentRegion, c.CustomerId as CUST
    FROM dbo.FactTable ft 
    inner join dbo.Customer c
        ON ft.CustomerId = c.CustomerId
    inner join dbo.myTime mt
        ON ft.TimeId = mt.ID
    inner join dbo.Regions r
        ON ft.RegionId = r.RegionId
    WHERE mt.myhour = '09'
    GROUP BY c.HomeRegion, r.RegionName, c.CustomerId) uni_users
    GROUP by HomeRegion, CurrentRegion