小编Fra*_*ier的帖子

• 如何通过实体框架从Datetime字段获取平均时间？
• 如何从另一个日期中减去一个日期？

我想的是:

ObjectQuery<Visit> visits = myentitys.Visits;
            var uQuery =
            from visit in visits
            group visit by visit.ArrivalTime.Value.Day into g
            select new
            {
                 Day = g.Key,
                 Hours = g.Average(visit => (visit.LeaveTime.Value - visit.ArrivalTime.Value).TotalMinutes)
            };

获取按日分组的访客的平均停留时间.