我有一个名为testdb的MS Access数据库，表名称为table1。
该表具有2个字段BinNo和Prodcode。
BinNo有很多重复的行，我想对BinNo进行分组，只要它有重复的行即可创建新的别名列（如单个记录）。
给出以下数据：
+---------+----------+
| BinNo | Prodcode |
+---------+----------+
| Bin no1 | Pro 1 |
| Bin no1 | Pro 2 |
| Bin no1 | Pro 3 |
| Bin no2 | Pro 4 |
| Bin no2 | Pro 5 |
+---------+----------+
这是预期的结果：
+---------+-----------+-----------+-----------+
| BinNo | Prodcode1 | Prodcode2 | Prodcode3 |
+---------+-----------+-----------+-----------+
| Bin no1 | Pro 1 | Pro 2 | Pro 3 |
| Bin no2 | Pro 4 | Pro 5 | |
+---------+-----------+-----------+-----------+
答案 0 :(得分：2)
这回答了问题的原始版本。
这在MS Access中确实很痛苦。您可以使用条件聚合来做到这一点。这是一种方法：
error: ref updates forbidden inside quarantine environment子查询本质上实现了select t1.binno,
max(iif(seqnum = 1, prodcode, null)) as prodcode_1,
max(iif(seqnum = 2, prodcode, null)) as prodcode_2,
max(iif(seqnum = 3, prodcode, null)) as prodcode_3
from (select t1.*,
(select count(*)
from table1 as tt1
where tt1.binno = t1.binno and tt1.prodcode <= t1.prodcode
) as seqnum
from table1 as t1
) as t1
group by t1.binno;
，在MS Access中不可用。