SELECT Row Values WHERE MAX() 是 GROUP BY 查询中的列值
我该如何选择?我可以创建用户定义的聚合函数吗
How can I select like this? Can I create a User defined Aggregate Function
SELECT Max(A),(SELECT TOP 1 FROM TheGroup Where B=Max(A)) FROM MyTable
SELECT Max(A),(SELECT TOP 1 FROM TheGroup Where B=Max(A)) FROM MyTable
其中 MyTable 如下所示
where MyTable as Shown Below
A B C
--------------
1 2 S
3 4 S
4 5 T
6 7 T
我想要这样的查询
SELECT MAX(A),(B Where A=Max(A)),C FROM MYTable GROUP BY C
我期待的结果如下
MAX(A) Condition C
-----------------------
3 4 S
6 7 T
推荐答案
尝试以下查询:
SELECT TABLE1.A , TABLE2.B , TABLE1.C
FROM
(
SELECT MAX(A) AS A,C
FROM MYTable
GROUP BY C
) AS TABLE1
INNER JOIN
(
SELECT *
FROM MYTable
) AS TABLE2 ON TABLE1.A = TABLE2.A
SQLFIDDLE
您可以通过简单的连接查询来完成.join 查询总是比 In query 运行得更快.联接查询仅在执行查询时运行一次.我们可以使用 IN 查询存档相同的结果.
you can do it by simple join query . join query always run faster then In query . Join query run only one time at the time of execution of the query . we can archive same result by using IN query .
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