sql-server - 选择按周分组的 SQL 结果

Question

我想从下表中按周分组选择数据

 Date       Product Name   Sale
+----------+--------------+-----+
 14-05-11     a             2
 14-05-11     b             4 
 17-05-11     c             3
 19-05-11     a             6
 24-05-11     a             6
 29-05-11     a             6    

假设今天是 30-05-11

所以我的结果应该是这样的。

 Product Name         First Week   Second Week  Third Week
+--------------------+------------+------------+-------------+
   a                      12            6           2
   b                       0            0           4 
   c                       0            3           0  

有人会指导我如何编写 SQL 查询来实现此行为吗？

Answer 1

我认为这应该可以做到..

Select 
ProductName,
WeekNumber,
sum(sale)
from
(
    SELECT 
    ProductName,
    DATEDIFF(week, '2011-05-30', date) AS WeekNumber,
    sale
    FROM table
)
GROUP BY
ProductName,
WeekNumber