累積彙總列

Question

我可能需要一些SQL語句的幫助。所以，我有表「續」，它看起來像這樣：

cont_id  name  weight 
----------- ---------- ----------- 
1   1   10 
2   1   20 
3   2   40 
4   2   15 
5   2   20 
6   3   15 
7   3   40 
8   4   60 
9   5   10 
10   6   5 

然後我總結了重列，由名稱分組是：

name  wsum 
---------- ----------- 
2   75 
4   60 
3   55 
1   30 
5   10 
6   5 

而結果應該有一個積累柱看起來應該是：

name  wsum  acc_wsum 
---------- ----------- ------------ 
2   75   75 
4   60   135 
3   55   190 
1   30   220 
5   10   230 
6   5   235 

，但我沒能拿到最後的陳述工作..

編輯：此聲明做了（感謝戈登）

select t.*, 
    (select sum(wsum) from (select name, SUM(weight) wsum 
    from cont 
    group by name) 
    t2 where t2.wsum > t.wsum or (t2.wsum = t.wsum and t2.name <= t.name)) as acc_wsum 
from (select name, SUM(weight) wsum 
from cont 
group by name) t 
order by wsum desc 

Answer 1

所以，最好的方式做到這一點正在使用累積和：

select t.*, 
     sum(wsum) over (order by wsum desc) as acc_wsum 
from (<your summarized query>) t 

order by子句進行累加。

如果你不具備這種能力（在SQL Server 2012和Oracle），相關子查詢是一個簡單的方法來做到這一點，假設總結權重是不同的值：

select t.*, 
     (select sum(wsum) from (<your summarized query>) t2 where t2.wsum >= t.wsum) as acc_wsum 
from (<your summarized query>) t 

這應該工作在SQL的所有方言中。要處理累積重量可能有重複的情況：

select t.*, 
     (select sum(wsum) from (<your summarized query>) t2 where t2.wsum > t.wsum or (t2.wsum = t.wsum and t2.name <= t.name) as acc_wsum 
from (<your summarized query>) t 

Answer 2

試試這個

;WITH CTE 
AS 
(
SELECT *, 
ROW_NUMBER() OVER(ORDER BY wsum) rownum 
FROM @table1 
) 
SELECT 
c1.name, 
c1.wsum, 
acc_wsum= (SELECT SUM(c2.wsum) 
        FROM cte c2 
        WHERE c2.rownum <= c1.rownum) 
FROM CTE c1; 

，或者你可以加入的，而不是使用子查詢

;WITH CTE 
AS 
(
SELECT *, 
ROW_NUMBER() OVER(ORDER BY usercount) rownum 
FROM @table1 
) 
SELECT 
c1.name, 
c1.wsum, 
acc_wsum= SUM(c2.wsum) 
FROM CTE c1 
INNER JOIN CTE c2 ON c2.rownum <= c1.rownum 
GROUP BY c1.name, c1.wsum;