Question

我在MS Access中有一个表，如：

表

+-----+-----+-----+
| 1st | 2nd | 3rd |
+-----+-----+-----+
| A   |   1 | 100 |
| A   |   2 | 200 |
| A   |   3 | 300 |
| B   |   1 | 100 |
| B   |   2 | 200 |
| B   |   3 | 300 |
| C   |   1 | 100 |
| C   |   2 | 200 |
| C   |   3 | 300 |
+-----+-----+-----+

现在，我想从第3列中读取值，对其进行某种处理，然后将它们存储在另一个表中，例如：

摘要

+-----+---------+---------+
| 1st |   2nd   |   3rd   |
+-----+---------+---------+
| A   | 100/200 | 200/300 |
| B   | 100/200 | 200/300 |
| C   | 100/200 | 200/300 |
+-----+---------+---------+

换句话说，对于summary.2nd，这意味着：

select table.3rd FROM table where table.1st = A AND table.2nd = 1

除以

select table.3rd FROM table where table.1st = A AND table.2nd = 3

有人可以给我提示如何做到这一点吗？

也许是VBA / ADO Recordset等？

Answer 1

一种方法是条件聚合：

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            } catch (IOException e) {
                e.printStackTrace();
            }
}

Answer 2

尝试使用此SQL

INSERT INTO Summary 
SELECT DISTINCT a.[1st], 
                a.[3rd] / b.[3rd] AS [2nd], 
                a.[3rd] / c.[3rd] AS [3rd] 
FROM   ((tbl AS a 
         INNER JOIN tbl AS b 
                 ON a.[1st] = b.[1st]) 
        INNER JOIN tbl AS c 
                ON a.[1st] = c.[1st] ) 
WHERE  a.[2nd] = 1 
       AND b.[2nd] = 2 
       AND c.[2nd] = 3

Answer 3

这是使用计算的加入条件的另一种选择：

select 
    t1.[1st], 
    t1.[3rd]/t2.[3rd] as [2nd], 
    t2.[3rd]/t3.[3rd] as [3rd]
from 
    (
        [table] t1 inner join [table] t2 
        on t1.[1st] = t2.[1st] and t1.[2nd] = t2.[2nd]-1
    )
    inner join [table] t3 
    on t1.[1st] = t3.[1st] and t1.[2nd] = t3.[2nd]-2

由于2nd列的值1、2和3没有经过硬编码，因此这适用于2nd列中的值依次相差1的任何三个整数。

将[table]更改为表格名称。

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3 个答案: