问实体框架:实体子项中条件相反的查询结果错误

EN

 Partial Public Class Myobj
      Public Property id As Integer
      Public property name as string
      Public Overridable Property chld As ICollection(Of chld) = New HashSet(Of chld) 
   End Class


 Partial Public Class Myobj
     Public shared cond1 as DateTime
      <NotMapped> Public ReadOnly Property vls As integer
      Get
            Return chld.AsQueryable.Where(Function(t2) t2.date1<cond1).Select(Function(t3) t3.quantity).DefaultIfEmpty.Sum()
      End Get
End Property
End Class


Partial Public Class chld
    Public Property id As Integer
    Public Property date1 as DateTime
    Public Property quantity as Integer
    Public Property ParentID as integer
    Public Overridable Property MyObj1 As MyObj
End Class 

Dim dt1 as DateTime=CDate("08/08/2014")
Myobj.cond1=dt1

 Dim list1 = (From t In context.MyObj Select New With { _
      .Parent = t, _
      .chl =  (From t2 In t.chld.AsQueryable.Where(Function(t3) t3.Date1>=dt1) Select t2) 
}).ToList