每种类型客户的销售额百分比

Question

我想找出每种客户类型的每周销售额百分比。我可以看到数学，但我不知道如何编写查询。

SELECT 
    c.customerType as 'Customer Type', 
    DATEPART(WEEK, o.orderDate) as 'Week of the year', 
    COUNT(c.customerType)  as 'Number of sales' 
FROM
    [dbo].[Order] o
JOIN 
    Customer c ON c.id = o.customerId
GROUP BY 
    c.customerType, DATEPART(WEEK, o.orderDate)

此查询输出按客户类型分组的每次销售计数。

CustomerType  Week   Number of Sales
------------------------------------
Cash          36      248
Corporate     36       10
Personal      36        5
Cash          37      113
Corporate     37        3
Personal      37        2
Cash          38      136
Corporate     38        7
Personal      38        2
Cash          39      138
Corporate     39        4
Personal      39        3

Answer 1

您可以包装查询并使用 window 函数：

select 
    t.*,
    (100.0 * [Number of sales])
        /(sum([Number of sales]) over(partition by [Week of the year]) 
        [Percent of Total Sales]
from (
    select 
        c.customerType as [Customer Type], 
        datepart(week, o.orderDate) as [Week of the year], 
        count(c.customerType) as [Number of sales],     
    from [dbo].[Order] o
    join Customer c ON c.id = o.customerId
    group by c.customerType, datepart(week, o.orderDate), datepart(year, o.orderDate)
) t

备注：

在SQLServer中，最好使用括号而不是引号来定义标识符（引号通常保留给字符串）
100.0 中的 .0 很重要：它强制 SQLServer 执行小数除法（默认情况下它会进行整数除法，这不是你想要的）
我在组的定义中添加了年份；如果您的数据分布在几年内，您可能不希望将不同年份的同一周计算在一起

旁注：SQLServer 在混合 window 函数和聚合方面非常灵活。所以这个可能也有效：

select 
    c.customerType as [Customer Type], 
    datepart(week, o.orderDate) as [Week of the year], 
    count(c.customerType) as [Number of sales],     
    (100.0 * count(c.customerType))
        / (sum(count(c.customerType)) over(partition by datepart(week, o.orderDate)))
        as [Percent of Total Sales]
from [dbo].[Order] o
join Customer c ON c.id = o.customerId
group by c.customerType, datepart(week, o.orderDate), datepart(year, o.orderDate)

每种类型客户的销售额百分比

Percentage of Sales for each type of customer

sql-server

ssms

percentage