Linq问题处理select中的空值

我的解决方案中有以下实体

public class UtilityAccount : IObjectWithState 
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid UtilityAccountID { get; set; }
    public string Account { get; set; }
    [ForeignKey("Person")]
    public Guid PersonID { get; set; }
    public virtual Person Person { get; set; }
    public string ForeignID { get; set; }
    [NotMapped]
    public ObjectState ObjectState { get; set; }

    public virtual ICollection<Utility> Utilities { get; set; }

    public UtilityAccount()
    {
        Utilities = new List<Utility>();
    }
}

public class Utility : IObjectWithState 
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid UtilityID { get; set; }
    [ForeignKey("UtilityAccount")]
    public Guid UtilityAccountID { get; set; }
    public virtual UtilityAccount UtilityAccount { get; set; }
    public Guid? ServiceAddressID { get; set; }
    [ForeignKey("ServiceAddressID")]
    public virtual Address ServiceAddress { get; set; }
    [NotMapped]
    public ObjectState ObjectState { get; set; }
    public double CurrentBalance { get; set; }
    public double? PendingPaymentTotal { get; set; }
    public string ForeignID { get; set; }
    [ForeignKey("UtilityType")]
    public Guid UtilityTypeID { get; set; }
    public virtual UtilityType UtilityType { get; set; }
    public virtual ICollection<UtilityBill> UtilityBills { get; set; }
    public virtual ICollection<IncomingUtilityPayment> IncomingPayments { get; set; }

    public Utility()
    {
        UtilityBills = new List<UtilityBill>();
        IncomingPayments = new List<IncomingUtilityPayment>();
    }
}

public class IncomingUtilityPayment : IObjectWithState
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid IncomingPaymentID { get; set; }
    public string ForeignID { get; set; }
    [ForeignKey("Utility")]
    public Guid UtilityID { get; set; }
    public virtual Utility Utility { get; set; }
    public DateTime PaymentDate { get; set; } 

    public IncomingPaymentStatus IncomingPaymentStatus { get; set; }
    public double? UtilityAmount { get; set; }
    public double? ConvenienceFee { get; set; }
    public double? TotalAmount { get; set; }

    public string AuthCode { get; set; }
    public string AuthReference { get; set; }
    public string TenderType { get; set; }
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int PaymentIdent { get; set; }

    [NotMapped]
    public ObjectState ObjectState { get; set; }
}

在我把这一条款添加到声明中之前，一切都很顺利

o => o.Utilities.Select(p => p.IncomingPayments.Where(q => q.IncomingPaymentStatus == IncomingPaymentStatus.Pending || q.IncomingPaymentStatus == IncomingPaymentStatus.Processed ))

我想我的问题最终会成为我在Linq条款中写错的东西。我得到的错误是

The Include path expression must refer to a navigation property defined on the type. Use dotted paths for reference navigation properties and the Select operator for collection navigation properties.

参数名称：路径

我可以毫无疑问地使用以下语句

o => o.Utilities.Select(p => p.IncomingPayments)

---

一旦我在中添加where子句，就会出现错误

我不熟悉EntityFramework或linq to entities，但如果它与linq to object一样，您可以：

在使用

链接之前，添加一个
。其中（p=>p.IncomingPayments！=null）
。像这样选择（）

o.Utilities.Where(p => p.IncomingPayments != null)
           .Select(p => p.IncomingPayments.Where(q => q.IncomingPaymentStatus == IncomingPaymentStatus.Pending || q.IncomingPaymentStatus == IncomingPaymentStatus.Processed))

结果将是嵌套的IEnumerable，即
IEnumerable

如果你真的需要一个
IEnumerable
，那么
。选择many（）
来播放

o.Utilities.Where(p => p.IncomingPayments != null)
           .SelectMany(p => p.IncomingPayments)
           .Where(q => q.IncomingPaymentStatus == IncomingPaymentStatus.Pending || q.IncomingPaymentStatus == IncomingPaymentStatus.Processed)

希望此帮助
我认为这将解决我的问题，但当我使用您提供的代码时，我遇到以下错误，Include path表达式必须引用在类型上定义的导航属性。使用虚线路径作为参考导航属性，选择运算符作为集合导航属性。参数名称：path似乎SelectMany在这种情况下不起作用。它让我使用Select，可能是因为它在include语句中。如果语句中没有where子句，它可以正常工作，但只要我在上面添加where我得到的错误列表，Include（）似乎就不能包含筛选（where原因）。
o.Utilities.Where(p => p.IncomingPayments != null)
           .SelectMany(p => p.IncomingPayments)
           .Where(q => q.IncomingPaymentStatus == IncomingPaymentStatus.Pending || q.IncomingPaymentStatus == IncomingPaymentStatus.Processed)