相关疑难解决方法(0)

正如标题所示,我想选择用a组成的每组行的第一行GROUP BY.

具体来说,如果我有一个purchases看起来像这样的表:

SELECT * FROM purchases;

我的输出:

id | customer | total
---+----------+------
 1 | Joe      | 5
 2 | Sally    | 3
 3 | Joe      | 2
 4 | Sally    | 1

我想查询每个产品id的最大购买量(total)customer.像这样的东西:

SELECT FIRST(id), customer, FIRST(total)
FROM  purchases
GROUP BY customer
ORDER BY total DESC;

预期产出:

FIRST(id) | customer | FIRST(total)
----------+----------+-------------
        1 | Joe      | 5
        2 | Sally    | 3

我需要将此SQL语句翻译成Linq-Entity查询...

SELECT name, count(name) FROM people
GROUP by name

我在oracle数据库中有两列

+---------+---------+
| Column1 | Column2 |
+---------+---------+
| A       | 1       |
| A       | 2       |
+---------+---------+

我希望退出数据,就像我将获得数据一样

+---------+---------+
| Column1 | Column2 |
+---------+---------+  
| A       | 1,2     |
+---------+---------+

请给我解决方案.