Linq从每个类别中取3条记录

我有列"类别"在我的表，我想从每个类别采取3行。下面是我的表的例子:

 ID | Category | Text
----------------------
 01 |    TST   | Text here
 02 |    TST   | Text2 here
 03 |    TST   | Text3 here
 04 |    TST   | Text4 here
 01 |   TST02  | Text here
 02 |   TST02  | Text2 here
 03 |   TST02  | Text3 here
 04 |   TST02  | Text4 here
 05 |   TST02  | Text5 here

这就是我想回去的原因:

 ID | Category | Text
----------------------
 01 |    TST   | Text here
 02 |    TST   | Text2 here
 03 |    TST   | Text3 here
 01 |   TST02  | Text here
 02 |   TST02  | Text2 here
 03 |   TST02  | Text3 here

我如何用LINQ完成它?

我试着这样做:

.GroupBy(x => x.Category).Take(3)

但是之后我不能使用。select

更新:当我使用SelectMany时，我得到一个错误:

Query Source could not be identified: ItemName = x, ItemType = System.Linq.IGrouping ' 2[System.String, add . models .]， Expression = from IGrouping ' 2 x in {from Notification w in value(NHibernate.Linq.NhQueryable ' 1[add . models .Notification]) where ([w]. add . models .Notification]。UserId == 04bccode -46d0-44f8-814b-346d5510acb8) order [w]。Time asc select [w] => GroupBy([w])。类别,[w])}

更新2:

下面是我的代码:

.GroupBy(x => x.Category).SelectMany(x => x.Take(3)).Select(
                                                     s =>
                                                     new NotificationData
                                                         {
                                                             Category = s.Category,
                                                             Text = s.Text,
                                                             Time = DateTime.Now.Subtract(s.Time)
                                                         })

var result = data.GroupBy(x => x.Category)
                 .SelectMany(x => x.Take(3));