SQL Server分組查詢某最大值的整條數據（包含linq寫法）

想實現如下效果，就是分組后時間最大的那一條數據：

 

1、SQL

        SELECT  *
        FROM    ( SELECT    * ,
                            ROW_NUMBER() OVER ( PARTITION BY RIP_GUID ORDER BY RU_CreatedTime DESC ) rn
                  FROM      RIP_FlowInfo
                ) t
        WHERE   t.rn <= 1;  

2、LINQ

    var groupQuery = from t in query group t by t.RIP_Guid into g select new { key = g.Key, source = g.OrderByDescending(tt => tt.RU_CreatedTime).FirstOrDefault() };