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LINQ-使用distinct和orderby编写查询_Linq_Sql Order By_Distinct - Fatal编程技术网

LINQ-使用distinct和orderby编写查询

LINQ-使用distinct和orderby编写查询,linq,sql-order-by,distinct,Linq,Sql Order By,Distinct,我对林克是个新手 假设我有下表: Incident ID DeviceID Time Info 1 1 5/2/2009 d 2 2 5/3/2009 c 3 2 5/4/2009 b 4 1 5/5/2009 a 在LINQ中,我如何编写一个查询来查找最新和不同的(设备ID上)事件集?我想要的结果是: ID DeviceID Time Info 3

我对林克是个新手

假设我有下表:

Incident 

ID DeviceID Time          Info

1    1      5/2/2009    d

2    2      5/3/2009    c

3    2      5/4/2009    b

4    1      5/5/2009    a
在LINQ中,我如何编写一个查询来查找最新和不同的(设备ID上)事件集?我想要的结果是:

ID DeviceID Time           Info

3    2      5/4/2009    b

4    1      5/5/2009    a

您是否必须创建一个IEqualityComparer来执行此操作?

您可以通过以下方式获取每个设备的最新事件(这是我理解您的问题的方式):


是的,正是我想要的。谢谢
var query = 
   incidents.GroupBy(incident => incident.DeviceID)
            .Select(g => g.OrderByDescending(incident => incident.Time).First())
            .OrderBy(i => i.Time); // only add if you need results sorted
int filterDeviceID = 10;

var incidents = (from incident in incidentlist
                where incident.DeviceID == filterDeviceID
                select incident).Distinct().OrderBy( x => x.Time);