C# 在实体框架中加载具有筛选条件的子对象记录

采用实体框架设计了数据访问层，给出了PackageInstance对象的示例POCO结构

public class PackageInstance
{
  public virtual long PackageInstanceId {set;get;}
  public virtual boolean IsDeleted {set;get;}
  public virtual List<Session> Sessions {set;get;}
}

public class Session
{
  public virtual long SessionId {set;get;}
  public virtual long PackageInstanceId {set;get;}
  public virtual boolean IsDeleted {set;get;}
  public virtual List<Note> Notes {set;get;}
}

public class Note
{
  public virtual long NoteId {set;get;}
  public virtual long SessionId {set;get;}
  public virtual boolean IsDeleted {set;get;}
  public virtual List<Documents> Document {set;get;}
}

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如何消除多个DB调用？

免责声明：我是项目的所有者

EF+查询IncludeFilter功能允许筛选相关实体。它支持EF5

var packageInstanceDB = entity.PackageInstances
    .IncludeFilter(x => x.Sessions)
    .IncludeFilter(x => x.Sessions.Select(y => y.Notes.Where(sn => !sn.IsDeleted)))
    .IncludeFilter(x => x.Sessions.SelectMany(y => y.Notes.Where(sn => !sn.IsDeleted)).Select(z => z.Documents.Where(sn => !sn.IsDeleted)))
    .First(p => p.PackageInstanceId == purhcaseSessionId);

注意：必须包括每个路径

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维基：

你的代码被遵守了吗？错了。用实际代码快照更新了问题。这里也发生了多个DB呼叫。你能给我们举个例子并解释一下你想要得到什么吗？首先要感谢Jonathan Magnan。。。在4个月之前，我用EFP替换了现有代码，它提供了更好的性能。。。。。

var packageInstanceDB = entity.PackageInstances
    .IncludeFilter(x => x.Sessions)
    .IncludeFilter(x => x.Sessions.Select(y => y.Notes.Where(sn => !sn.IsDeleted)))
    .IncludeFilter(x => x.Sessions.SelectMany(y => y.Notes.Where(sn => !sn.IsDeleted)).Select(z => z.Documents.Where(sn => !sn.IsDeleted)))
    .First(p => p.PackageInstanceId == purhcaseSessionId);