sql server从组中选择第一行

问题描述：

我有这样的桌子:

a          b
1          23
1          2
1          7
2          9
2          11

我想从GROUP BY a"查询中选择第一行(顺序无关紧要)，结果应该是

I want to select the first row(order does not matter) from a "GROUP BY a" query , the result should be

a          b
1          23
2          9

我正在使用 SQL SERVER 2008 如何为此编写查询?

I am using SQL SERVER 2008 how to write the query for this?

答

如果按照您的指示，顺序无关紧要，任何聚合函数 b 就足够了.

If as you indicated, order doesn't matter, any aggregate function on b would be sufficient.

SELECT a, b = MIN(b)
FROM   YourTable
GROUP BY
       a