Question

使用SQL如何将表中的2列相乘并将它们的总和除以另一列的总和？

我的表格如下：

    A  |  B  | A*B 
   ----|-----|------
    1  |  2  |   2
    5  |  4  |  20
    3  |  5  |  15

让我们假设C = sum(A*B)和D = sum(B)。我想计算C/D。

例如，C = sum(A*B) = 37和D = sum(B) = 11以上C/D = 3.367

Answer 1

这应该完全符合您的要求

SELECT (SUM(A*B)) / SUM(B) From table;

Answer 2

试试这个：

SELECT f1, f2, (f2 / f1) as result from 
(SELECT SUM(B) as f1, SUM(A*B) as f2 FROM table)

这将解决您的问题。

Answer 3

我在SQL Server中尝试过类似的东西，可能会有所帮助：

DECLARE @table TABLE
(
   A INT,
   B INT
) 

INSERT INTO @table 
VALUES
(1,2),
(5,4),
(3,5)

SELECT SUM(a * b)                                                          [A*B],
       SUM(b)                                                              [B],
       CAST(SUM(a * b) / CAST(SUM(b) AS DECIMAL(13, 3)) AS DECIMAL(13, 3)) [RESULT]
FROM   @table

Answer 4

如果使用完整

，请尝试此操作

CREATE TABLE #Table1
    ([Name] varchar(5), [Quality] int, [No] int)
;

INSERT INTO #Table1
    ([Name], [Quality], [No])
VALUES
  ( 'a' ,  80 , 2),
('a',   85 , 3),
('a'  , 90 , 4),
('b'  , 85 , 2),
('b',   90,  1)

;


Declare @SumNo int,@DevideNo int,@Avg float

SET @SumNo=(SELECT SUM(Quality * No) as totalVal FROM #Table1) 
SET @DevideNo=(SELECT SUM(Quality) FROM #Table1)
SET @Avg = @SumNo/@DevideNo
PRINT @Avg

如何计算SQL聚合？

4 个答案: