Question

我有两个表，需要创建一个列出所有第一个表的查询和一个第二个表中的字段，其中第二个表中的第二个字段是最大值。

Table1
MatID | MatCode | Name |
-----------------------
1     | A       | Ex1  |
2     | B       | Ex2  |
3     | C       | Ex3  |

Table 2
MatID | MatCode | OtherName | Count |
------------------------------------
1     | A       | Red       | 5     |
1     | A       | Blue      | 15    |
1     | A       | Green     | 2     |
2     | B       | Red       | 25    |
2     | B       | Blue      | 3     |
2     | B       | Green     | 1     |
3     | C       | Red       | 2     |
3     | C       | Blue      | 3     |
3     | C       | Green     | 11    |

结果将是

MatID | MatCode | Name | OtherName |
-----------------------------------
1     | A       | Ex1  | Blue
2     | B       | Ex2  | Red
3     | C       | Ex3  | Green

希望这很清楚。

先谢谢

Answer 1

我建议使用相关的子查询：

select t1.*,
       (select top 1 t2.OtherName
        from table2 as t2
        where t2.MatId = t1.MatId
        order by count desc, matid  -- to prevent duplicates
       ) as OtherName
from table1 as t1;

Answer 2

尝试：

SELECT Z.MatID, Z.MatCode, Z.Name, C.OtherName
FROM
(SELECT A.MatID, A.MatCode, A.Name, MAX(Count) as Max_Count
FROM
Table1 A INNER JOIN table2 B
ON A.MatID = B.MatID AND A.MatCode = B.MatCode
GROUP BY A.MatID, A.MatCode, A.Name ) Z
INNER JOIN Table2 C
ON Z.MatID = C.MatID AND Z.MatCode = C.MatCode AND Z.Max_Count = C.Count;

Access嵌套选择查询获取具有最大值的行

2 个答案: