SQL Server 2008 R2，为另一列的每个不同值选择一列

问题描述

在 SQL Server 2008 R2 上，我想为另一列的每个不同值选择一列的一个值.

On SQL server 2008 R2, I would like to select one value of a column for each distinct value of another column.

例如

 name   id_num
 Tom      53
 Tom      60
 Tom      27
 Jane     16
 Jane     16
 Bill     97
 Bill     83

我需要为每个不同的名称获取一个 id_num，例如

I need to get one id_num for each distinct name, such as

 name   id_num
 Tom      27
 Jane     16
 Bill     97

对于每个名称，可以随机选取 id_num(不需要是 max 或 min)，只要与名称相关联即可.

For each name, the id_num can be randomly picked up (not required to be max or min) as long as it is associated with the name.

例如，对于比尔，我可以选择 97 或 83.任何一个都可以.

For example, for Bill, I can pick up 97 or 83. Either one is ok.

我知道如何编写 SQL 查询.

I do know how to write the SQL query.

谢谢

推荐答案

SELECT 
 name,MIN(id_num)
FROM YourTable
GROUP BY name

更新:如果你想随机选择 id_num，你可以试试这个

UPDATE: If you want pick id_num randomly, you may try this

WITH cte AS (
  SELECT 
    name, id_num,rn = ROW_NUMBER() OVER (PARTITION BY name ORDER BY newid())
  FROM YourTable
)
SELECT *
FROM cte
WHERE rn = 1

SQL 小提琴演示

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