Question

我不确定发生了什么变化，但是，在回到几周前我正在处理的应用程序之后，我的.Include()调用不再适用于我的一个相关表格。奇怪的是它适用于不同的表。以下是一些代码，其中的注释显示了我的结果：

//Get the order and nothing else.
using (OrderEntity orderContext = new OrderEntity(OrdersConnectionString)) {
    var query = from order in orderContext.ShippingOrders
                where order.ShipperId == shippingId
                select order;

    //I got a value!
    shippingOrder = query.ToList().FirstOrDefault();
}

//Get the line item and nothing else.
using (OrderEntity orderContext = new OrderEntity(OrdersConnectionString)) {
    var query = from orderItem in orderContext.ShippingOrderItems
                where orderItem.ShipperId == shippingId
                select orderItem;

    //I got a value!
    shippingOrderItems = query.ToList();
}

这是我感到困惑的地方：

//Get the order *AND* the line item
using (OrderEntity orderContext = new OrderEntity(OrdersConnectionString)) {
    var query = from order in orderContext.ShippingOrders.Include("ShippingOrderItems")
                where order.ShipperId == shippingId
                select order;

    //I get a ShippingOrder result, but no items are returned.  I used the SQL Server Profiler and saw the SQL that got executed; it contains the item, EF just isn't loading the object.
    shippingOrder = query.ToList().FirstOrDefault();
}

我可以获取不同相关表的结果。这让我觉得EF缺少我的订单和订单项表之间的关系，但是，我不知道如何解决这个问题。

修改：这是订单实体

/// <summary>
/// No Metadata Documentation available.
/// </summary>
[EdmEntityTypeAttribute(NamespaceName="OrderModel", Name="ShippingOrder")]
[Serializable()]
[DataContractAttribute(IsReference=true)]
public partial class ShippingOrder : EntityObject
{
    #region Factory Method

    /// <summary>
    /// Create a new ShippingOrder object.
    /// </summary>
    /// <param name="shipperId">Initial value of the ShipperId property.</param>
    public static ShippingOrder CreateShippingOrder(global::System.String shipperId)
    {
        ShippingOrder shippingOrder = new ShippingOrder();
        shippingOrder.ShipperId = shipperId;
        return shippingOrder;
    }

    #endregion
    #region Primitive Properties

    /// <summary>
    /// No Metadata Documentation available.
    /// </summary>
    [EdmScalarPropertyAttribute(EntityKeyProperty=true, IsNullable=false)]
    [DataMemberAttribute()]
    public global::System.String ShipperId
    {
        get
        {
            return _ShipperId;
        }
        set
        {
            if (_ShipperId != value)
            {
                OnShipperIdChanging(value);
                ReportPropertyChanging("ShipperId");
                _ShipperId = StructuralObject.SetValidValue(value, false);
                ReportPropertyChanged("ShipperId");
                OnShipperIdChanged();
            }
        }
    }
    private global::System.String _ShipperId;
    partial void OnShipperIdChanging(global::System.String value);
    partial void OnShipperIdChanged();

    /// <summary>
    /// No Metadata Documentation available.
    /// </summary>
    [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)]
    [DataMemberAttribute()]
    public global::System.String OrderNumber
    {
        get
        {
            return _OrderNumber;
        }
        set
        {
            OnOrderNumberChanging(value);
            ReportPropertyChanging("OrderNumber");
            _OrderNumber = StructuralObject.SetValidValue(value, true);
            ReportPropertyChanged("OrderNumber");
            OnOrderNumberChanged();
        }
    }
    private global::System.String _OrderNumber;
    partial void OnOrderNumberChanging(global::System.String value);
    partial void OnOrderNumberChanged();

    /// <summary>
    /// No Metadata Documentation available.
    /// </summary>
    [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)]
    [DataMemberAttribute()]
    public Nullable<global::System.DateTime> OrderDate
    {
        get
        {
            return _OrderDate;
        }
        set
        {
            OnOrderDateChanging(value);
            ReportPropertyChanging("OrderDate");
            _OrderDate = StructuralObject.SetValidValue(value);
            ReportPropertyChanged("OrderDate");
            OnOrderDateChanged();
        }
    }
    private Nullable<global::System.DateTime> _OrderDate;
    partial void OnOrderDateChanging(Nullable<global::System.DateTime> value);
    partial void OnOrderDateChanged();

    /// <summary>
    /// No Metadata Documentation available.
    /// </summary>
    [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)]
    [DataMemberAttribute()]
    public global::System.String CustomsComment
    {
        get
        {
            return _CustomsComment;
        }
        set
        {
            OnCustomsCommentChanging(value);
            ReportPropertyChanging("CustomsComment");
            _CustomsComment = StructuralObject.SetValidValue(value, true);
            ReportPropertyChanged("CustomsComment");
            OnCustomsCommentChanged();
        }
    }
    private global::System.String _CustomsComment;
    partial void OnCustomsCommentChanging(global::System.String value);
    partial void OnCustomsCommentChanged();

    #endregion

    #region Navigation Properties

    /// <summary>
    /// No Metadata Documentation available.
    /// </summary>
    [XmlIgnoreAttribute()]
    [SoapIgnoreAttribute()]
    [DataMemberAttribute()]
    [EdmRelationshipNavigationPropertyAttribute("OrderModel", "FK_ShippingOrderItem_ShippingOrder", "ShippingOrderItem")]
    public EntityCollection<ShippingOrderItem> ShippingOrderItems
    {
        get
        {
            return ((IEntityWithRelationships)this).RelationshipManager.GetRelatedCollection<ShippingOrderItem>("OrderModel.FK_ShippingOrderItem_ShippingOrder", "ShippingOrderItem");
        }
        set
        {
            if ((value != null))
            {
                ((IEntityWithRelationships)this).RelationshipManager.InitializeRelatedCollection<ShippingOrderItem>("OrderModel.FK_ShippingOrderItem_ShippingOrder", "ShippingOrderItem", value);
            }
        }
    }

    /// <summary>
    /// No Metadata Documentation available.
    /// </summary>
    [XmlIgnoreAttribute()]
    [SoapIgnoreAttribute()]
    [DataMemberAttribute()]
    [EdmRelationshipNavigationPropertyAttribute("OrderModel", "FK_ShippingOrderItemTracking_ShippingOrder", "ShippingOrderTracking")]
    public EntityCollection<ShippingOrderTracking> ShippingOrderTrackings
    {
        get
        {
            return ((IEntityWithRelationships)this).RelationshipManager.GetRelatedCollection<ShippingOrderTracking>("OrderModel.FK_ShippingOrderItemTracking_ShippingOrder", "ShippingOrderTracking");
        }
        set
        {
            if ((value != null))
            {
                ((IEntityWithRelationships)this).RelationshipManager.InitializeRelatedCollection<ShippingOrderTracking>("OrderModel.FK_ShippingOrderItemTracking_ShippingOrder", "ShippingOrderTracking", value);
            }
        }
    }

    #endregion
}

Answer 1

我还不确定问题的原因是什么。我决定放弃我的数据库并重新创建我的表（以及主键和外键）并再次迁移所有数据。它实际上修复了它，但是，我不确定最终会有什么不同。我没有记录任何异常，并且基于SQL Server Profiler，它看起来正在执行正确的查询。

Answer 2

你也可以试试这个：

if (Order.shippingId != null && Order.shippingId > 0)
    orderContext.LoadProperty(Orders, Order => Order.ShippingOrderItems);

这将获取ShippingOrderItems中的匹配订单ID。

包括不使用Entity Framework查询

2 个答案: