entity-framework - .include 在以下查询中不包括真的

Question

var diaryEntries = (from entry in repository.GetQuery<OnlineDiary.Internal.Model.DiaryEntry>()
                               .Include("DiaryEntryGradeChangeLog")
                               .Include("DiaryEntryAction")
                                           join diary in repository.GetQuery<OnlineDiary.Internal.Model.OnlineDiary>()                                           
                                           on entry.DiaryId equals diary.Id
                                           group entry
                                           by diary
                                           into diaryEntriesGroup
                                           select new { Diary = diaryEntriesGroup.Key,
                                               DiaryEntry = diaryEntriesGroup.OrderByDescending(diaryEntry => diaryEntry.DateModified).FirstOrDefault(),
                                           });

此查询不包括“DiaryEntryGradeChangeLog”和“DiaryEntryAction”导航属性，此查询有什么问题？

我已经从查询中删除了联接并按照下面的方法进行了更正，但它仍然没有填充任何内容

var diaryEntries = from entry in repository.GetQuery<OnlineDiary.Internal.Model.DiaryEntry>()
                                   .Include("DiaryEntryGradeChangeLog").Include("DiaryEntryAction")
                                   .Where(e => 1 == 1)
                                       group entry
                                       by entry.OnlineDiary
                                       into diaryEntryGroups
                                       select 
                                       new { DiaryEntry = diaryEntryGroups.OrderByDescending(diaryEntry => diaryEntry.DateModified).FirstOrDefault() };

Answer 1

它不会。Include仅当查询的形状不改变时才有效（按设计）。如果您使用此查询，它将起作用，因为查询的形状仍然相同（OnlineDiary.Internal.Model.DiaryEntry）：

var diaryEntries = (from entry in repository.GetQuery<OnlineDiary.Internal.Model.DiaryEntry>()
                           .Include("DiaryEntryGradeChangeLog")
                           .Include("DiaryEntryAction");

但是，一旦您使用手动连接、分组或投影 ( select new { })，您就改变了查询的形状，所有Include调用都将被跳过。

编辑：

您必须使用这样的东西（未经测试）来获取相关数据：

var diaryEntries = from entry in repository.GetQuery<OnlineDiary.Internal.Model.DiaryEntry>()
                   group entry by entry.OnlineDiary into diaryEntryGroups
                   let data = diaryEntryGroups.OrderByDescending(diaryEntry => diaryEntry.DateModified).FirstOrDefault()
                   select new { 
                       DiaryEntry = data,
                       GradeChangeLog = data.DiaryEntryGradeChangeLog,
                       Action = data.DiaryEntryAction
                   };

或任何类似的查询，您手动填充投影到匿名或未映射类型的关系的属性。