SQL窗與分組

Question

累計總和我有一個表像這樣

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

我想有一個帳戶累計值列

|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  | 

我已經嘗試在做的通過使用此窗口功能儘管它似乎沒有返回正確的值

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

Answer 1

正確的勝利dow功能將使用partition by：

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