每个日期期间合格客户的总购买百分比

Question

我需要找到按月购买巧克力的客户所售出巧克力的百分比。以下面的示例表为例，该表仅包含一个月条目：

Cust_Id     Customer    Quantity    Item        Amount in $     Date         Month and year
1           Maria       2           chocolate   10                 01/01/2020   1-2020
1           Maria       1           banana      5                  01/01/2020   1-2020
1           Maria       3           cookies     3                  01/01/2020   1-2020
2           Carlos      5           cookies     10                 01/01/2020   1-2020
2           Carlos      3           banana      3                  01/01/2020   1-2020
3           Jose        1           banana      5                  01/01/2020   1-2020
3           Jose        1           chocolate   3                  01/01/2020   1-2020
4           Anne        10          chocolate   20                 01/01/2020   1-2020
4           Anne        1           banana      5                  01/01/2020   1-2020
4           Anne        10          cookies     15                 01/01/2020   1-2020

在2020年1月购买巧克力的客户中（玛丽亚，何塞和安妮，但[[否卡洛斯），购买总金额中有多少（以百分比为单位）用于巧克力？

通过Excel中的数据透视表的解决方案：

Month   1 2020
Customer Name   SUM of Amount in $  Total amount of purchase    Overall %
Anne            20                  40  
Jose            3                   8   
Maria           10                  18  
Grand Total     33                  66                         50.00%

如何确定仅在该日期段内通过SQL购买了巧克力的客户在每个日期段内售出巧克力的百分比？

Answer 1

您可以使用条件聚合：

select customer, 
       sum(case when item = 'chocolate' then amount end) as chocolate_amount,
       sum(amount) as total_amount,
       (sum(case when item = 'chocolate' then amount end) /
        sum(amount)
       ) as chocolate_ratio
from t
where date >= '2020-01-01' and date < '2020-02-01'
group by customer
having sum(case when item = 'chocolate' then 1 else 0 end) > 0