SQL为一个大表中的每个项添加正在运行的总计列

Question

我想根据5种类型的事务（比如事务a、B、C、D、E）计算一个运行总数。但我在这张表中有一千多种不同的产品，每种产品在不同的日子都可能有数百万的交易记录。

所以表格看起来是这样的：

ProductID   A   B   C   D   E   Running Total
   1       10   0   5   0   5       20
   2       15   0   0   0   0       15
   3       20   5   0   10  0       35
   1       10   0   0   0   0       30 (20 for product 1, plus 10 for product 1 again)
   3       12   0   33  0   0       80 (35 for product 3, plus 45 for product 3 again)

Answer 1

ANSI标准方法是使用sum()作为窗口函数：

select t.*,
       sum(a + b + c + d + e) over (partition by productid order by <datetimecol>) as RunningTotal
from table t;

SQL表表示无序的集合，因此您需要一个指定排序的列。我猜某个地方有一个日期/时间栏。

大多数数据库都支持标准语法：Oracle、SQL Server 2012+、Postgres、Teradata和DB2。

Answer 2

测试数据

DECLARE @TABLE TABLE (ProductID INT, A INT,  B INT,  C INT,  D INT,  E INT)  
INSERT INTO @TABLE VALUES
(1 ,10,   0,   5 ,  0 ,  5),  --     20
(2 ,15,   0,   0 ,  0 ,  0),  --     15
(3 ,20,   5,   0 ,  10,  0),  --     35
(1 ,10,   0,   0 ,  0 ,  0),  --     30 (20 for product 1, plus 10 for product 1 again)
(3 ,12,   0,   33,  0 ,  0)   --    80

查询

;WITH CTE AS
(
    select *
          ,ROW_NUMBER() OVER (PARTITION BY ProductID ORDER BY ProductID ASC) rn 
    from @TABLE  
)
SELECT ProductID 
      ,A 
      ,B
      ,C
      ,D
      ,E
      ,runningTotal
FROM CTE c
 cross apply (select sum(A+B+C+D+E) as runningTotal
                from CTE
                where rn <= c.rn
                  and ProductID = c.ProductID
              ) as rt

结果

╔═══════════╦════╦═══╦════╦════╦═══╦══════════════╗
║ ProductID ║ A  ║ B ║ C  ║ D  ║ E ║ runningTotal ║
╠═══════════╬════╬═══╬════╬════╬═══╬══════════════╣
║         1 ║ 10 ║ 0 ║  5 ║  0 ║ 5 ║           20 ║
║         1 ║ 10 ║ 0 ║  0 ║  0 ║ 0 ║           30 ║
║         2 ║ 15 ║ 0 ║  0 ║  0 ║ 0 ║           15 ║
║         3 ║ 20 ║ 5 ║  0 ║ 10 ║ 0 ║           35 ║
║         3 ║ 12 ║ 0 ║ 33 ║  0 ║ 0 ║           80 ║
╚═══════════╩════╩═══╩════╩════╩═══╩══════════════╝