实体框架按日期选择每个组中的一个

Question

我有一个这样的表(表名:帖子):

+----+--------------------------+-------+------------+
| id |         content          | type  |    date    |
+----+--------------------------+-------+------------+
|  0 | Some text                | TypeA | 2013-04-01 |
|  1 | Some older text          | TypeA | 2012-03-01 |
|  2 | Some even older texttext | TypeA | 2011-01-01 |
|  3 | A dog                    | TypeB | 2013-04-01 |
|  4 | And older dog            | TypeB | 2012-03-01 |
|  5 | An even older dog        | TypeB | 2011-01-01 |
+----+--------------------------+-------+------------+

使用LINQ表达式我想找到每种类型的最新内容,所以结果应该是

Some text | TypeA 
A dog     | TypeB

我已经尝试了一些事情,但没有指出非工作表达式.

Answer 1

如果你想获得整个帖子.你可以试试这个:

var query = Posts.GroupBy(p => p.Type)
                  .Select(g => g.OrderByDescending(p => p.Date)
                                .FirstOrDefault()
                   )