Sql 划分顺序记录

我在MS Access中有一个表，如：

表格

+-----+-----+-----+
|第一|第二|第三|
+-----+-----+-----+
|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列读取值，对其进行某种操作，并将其存储到另一个表中，如：

摘要

+-----+---------+---------+
|第一|第二|第三|
+-----+---------+---------+
|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

有人能告诉我怎么做吗

可能是VBA/ADO记录集等

试试这个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 

---

一种方法是条件聚合：

select [1st],
       max(iif([2nd] = 1, [3rd], null)) / max(iif([2nd] = 2, [3rd], null)) as [2nd],
       max(iif([2nd] = 2, [3rd], null)) / max(iif([2nd] = 3, [3rd], null)) as [3rd]
from t
group by [1st];

---

下面是另一种选择，使用计算的联接条件：

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不是硬编码的，因此这适用于

2nd

列中任何三个值按顺序相差一的整数

---

将

[table]

更改为您的表名。

@Jbill。非常感谢。