Sql 如何根据日期范围和最大日期分组求和值？

我有如下数据集——按周和产品汇总的数量和销售额

Week    Product     Quantity    Sales
----    -------     --------    -----
1       12a         6           600
2       12a         4           400
3       12a         3           300
4       12a         1           100
5       12a         3           300 
6       12a         1           100
7       12a         4           400 
8       12a         6           600
9       12a         2           200

对于每一周，我需要将该周的数量和销售额加上前3周的总和

预期结果将是：

Week    Product     Quantity    Sales
----    -------     --------    -----
1       12a         14          1400  --> Week 1 + Week 2 + Week 3 + Week 4 but row labeled Week 1
2       12a         11          1100

我觉得我需要一个每周评估的循环

使用窗口功能：

select t.*,
       sum(quantity) over (partition by product
                        order by week
                        rows between current row and 3 following
                       ) as quantity,
       sum(sales) over (partition by product
                        order by week
                        rows between current row and 3 following
                       ) as sales
from t;