linq group by：良好的语法但奇怪的输出

我的查询的语法很好但不是输出，这真的很奇怪。

我有下表：

| AppointID | UserID | AppointSet | AppointAttended | AppointCancelled | AppointRescheduled | AppointmentDatetime | 1 | 1 | 2/15/2011 | | 3/11/2011 | | 3/15/2011 | 2 | 1 | 2/17/2011 | | | 3/11/2011 | 3/10/2011 | 3 | 1 | 3/11/2011 | 3/11/2011 | | | 3/25/2011 | 4 | 1 | 3/10/2011 | | 3/11/2011 | | 3/11/2011 

我要做的是创建以下输出，按天计算活动。

 | Date | Set | Attended | Rescheduled | Cancelled | | 3/10/2011 | 1 | | | | | 3/11/2011 | 1 | 1 | 1 | 2 | 

请注意，我已将字段AppointAttended，AppointCancelled和AppointRescheduled定义为可为空，因为可能没有这些日期。

查询如下：

 var OutputMonthlyActivity = from appnt in MyDC.LeadsAppointments where appnt.UserID == TheUserID where (appnt.AppointSet.Year == TheDate.Year && appnt.AppointSet.Month == TheDate.Month) || (appnt.AppointAttended.Value.Year == TheDate.Year && appnt.AppointAttended.Value.Month == TheDate.Month) || (appnt.AppointRescheduled.Value.Year == TheDate.Year && appnt.AppointRescheduled.Value.Month == TheDate.Month) || (appnt.AppointCancelled.Value.Year == TheDate.Year && appnt.AppointCancelled.Value.Month == TheDate.Month) group appnt by new { SetOn = appnt.AppointSet.Date, ReschedOn = appnt.AppointRescheduled.Value.Date, Attended = appnt.AppointAttended.Value.Date, Cancelled = appnt.AppointCancelled.Value.Date } into daygroups select new ViewMonthlyActivityModel() { ViewDate = (from d in daygroups select d.AppointDatetime.Date).First(), CountTotalSetOnDay = (from c in daygroups where c.AppointSet.Date == daygroups.Key.SetOn select c.AppointID).Count(), CountAttendedOnDay = (from c in daygroups where c.AppointAttended.HasValue == true select c.AppointID).Count(), CountRescheduledOnDay = (from c in daygroups where c.AppointRescheduled.HasValue == true select c.AppointID).Count(), CountCancelledOnDay = (from c in daygroups where c.AppointCancelled.HasValue == true select c.AppointID).Count() }; 

TheDate是我传递的参数，表示我正在查询的月份（即3月1日）的日期。 问题是，除了3月份的所有日期之外，我将从2月的最后2天和4月的前2天获得结果。 此外，每天都有3排。

如果您有任何建议，那将非常感激。

谢谢。

Answer 1

问题似乎是你的组有一些匿名对象作为其关键。

您是按对象对每个约会进行分组：

 new { SetOn = appnt.AppointSet.Date, ReschedOn = appnt.AppointRescheduled.Value.Date, Attended = appnt.AppointAttended.Value.Date, Cancelled = appnt.AppointCancelled.Value.Date } into daygroups 

相反，您应该按实际键进行分组，例如AppointmentDatetime。

实际上，对于你想要做的事情，我认为你根本不需要分组。

假设以下示例数据：

 // First, get all appointments for the following user var TheUserID = 1; var appointments = from appointment in Appointments where appointment.UserID == TheUserID select appointment; // Then, find all unique dates var uniqueDates = appointments.Select(a => a.AppointSet) .Union(appointments.Where(a => a.AppointAttended.HasValue).Select(a => a.AppointAttended.Value)) .Union(appointments.Where(a => a.AppointCancelled.HasValue).Select(a => a.AppointCancelled.Value)) .Union(appointments.Where(a => a.AppointRescheduled.HasValue).Select(a => a.AppointRescheduled.Value)) .Union(appointments.Select(a => a.AppointmentDatetime)) // Filter by the month/year .Where(x => x.Month == TheDate.Month && x.Year == TheDate.Year) // Finally, select a new object for each unique date holding the counts .Select(x => new { Date = x, Cancelled = appointments.Where(a => a.AppointCancelled.HasValue && a.AppointCancelled.Value == x).Count(), Rescheduled = appointments.Where(a => a.AppointRescheduled.HasValue && a.AppointRescheduled.Value == x).Count(), Set = appointments.Where(a => a.AppointSet == x).Count(), Attended = appointments.Where(a => a.AppointAttended.HasValue && a.AppointAttended.Value == x).Count() }); 

这应该导致以下输出：

这是你想要做的吗？

Answer 2

你可以为每一列生成单独的计数，然后将它们连接在一起，就像这样（我只为AppointSet和AppointAttend完成它，但其余的都很简单）：

  var userAppoints = from appnt in MyDC.LeadsAppointments where appnt.UserID == TheUserID select appnt; var appntSets = from appnt in userAppoints where appnt.AppointSet.Year == TheDate.Year && appnt.AppointSet.Month == TheDate.Month group appnt by appnt.AppointSet into groups select new ViewMonthlyActivityModel() { ViewDate = groups.Key, CountTotalSetOnDay = groups.Count() }; var appntAttends = from appnt in userAppoints where appnt.AppointAttended != null && appnt.AppointAttended.Value.Year == TheDate.Year && appnt.AppointAttended.Value.Month == TheDate.Month group appnt by appnt.AppointAttended.Value into groups select new ViewMonthlyActivityModel() { ViewDate = groups.Key, CountAttendedOnDay = groups.Count() }; var allModels = appntSets.Concat(appntAttends).GroupBy(a => a.ViewDate, (date, models) => new ViewMonthlyActivityModel { ViewDate = date, CountTotalSetOnDay = models.Aggregate(0, (seed, model) => seed + model.CountTotalSetOnDay), CountAttendedOnDay = models.Aggregate(0, (seed, model) => seed + model.CountAttendedOnDay) }); 

Answer 3

如果您无法更改架构，我首先要重新整理数据：

 var appoinments = MyDC .LeadsAppointments .Select(la => new { somefields = somedata, //fill in the blanks resolveDate = la.AppointAttended ?? la.AppointCancelled ?? la.AppointRescheduled, resolveReason = la.AppointAttended != null ? 0 : la.AppointCancelled != null ? 1 : 2 }) 

现在我们制作2个日期与原因的平面表（0,1,2参加，取消，重新安排，4个设置）

 var setDates = appointments .Select(a => new {Date = a.Date, Reason = 4}); var otherDates = appointments .Select(a => new {Date = a.resolveDate,Reason = a.ResolveReason}); 

UnionAll上面的两个表格：

 var allDates = setDates.Concat(otherDates); 

和组：

 var groups = allDates.GroupBy(a => new{a.Date, a.Reason}); 

因此，查询特定日期：

 groups .Where(g => g.Key.Date == someDate) .Select(g=> new{g.Key.Reason, Count = g.Key.Count()}) 

应该（如果我的完全未经测试的代码接近工作）显示4行，每个原因都有计数。

不是你想要的形状，但如果你需要它就不会很难转动。