SQL窗与分组

Question

累计总和我有一个表像这样

|week_no|value|attribute| 
------------------------- 
| 1 | 3 | a | 
| 2 | 3 | a | 
| 3 | 3 | a | 
| 1 | 4 | b | 
| 2 | 4 | b | 
| 3 | 4 | b | 

我想有一个帐户累计值列

|week_no|value|attribute|accum_value| 
------------------------------------- 
| 1 | 3 | a |  3  | 
| 2 | 3 | a |  6  | 
| 3 | 3 | a |  9  | 
| 1 | 4 | b |  4  | 
| 2 | 4 | b |  8  | 
| 3 | 4 | b | 12  | 

我已经尝试在做的通过使用此窗口功能尽管它似乎没有返回正确的值

SUM(value) OVER(ORDER BY 1 ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS accum_value 

Answer 1

正确的胜利dow功能将使用partition by：

SUM(value) OVER (PARTITION BY attribute ORDER BY week_no 
       ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW 
       ) AS accum_value