NHibernate Eager 加载多级子对象 [英] NHibernate Eager loading multi-level child objects

问题描述

我有一个层次结构的对象，订单，联系人，地址:

I have a hierarchy of objects, Order, Contact, Address:

public class Order {
     public virtual Contact BillingContact { get; set; }
}

public class Contact {
     public virtual Address Address { get; set; }
}

我想通过 id 查询订单，并预先加载 billingcontact 及其地址.

I want to query an order by id, and eager load the billingcontact, along with it's address.

var criteria = DetachedCriteria.For<Order>()
     .SetFetchMode("BillingContact", FetchMode.Eager)

这个标准急切加载 BillingContact，但可以理解不是 BillingContact 的地址.如果我添加:

This criteria eager loads the BillingContact, but understandably not the address of the BillingContact. If i add:

     .SetFetchMode("BillingContact.Address", FetchMode.Eager)

这没有任何帮助.

另请注意，这些关系是单向的:

Also note that these relationships are unidirectional:

public OrderMap()
{
    References(x => x.BillingContact)
        .Not.Nullable()
        .Cascade.All();
}

public ContactMap()
{
    HasOne(x => x.Address)
        .Cascade.All()
        .FetchType.Join();
}

public AddressMap()
{
    Map(x => x.Address1);
} 

如何构建一个标准对象来加载孩子的孩子?这些关系映射看起来正确吗?

How can I construct a criteria object that will load the child of the child? Do these relationship mappings seem correct?

推荐答案

我相信您可能需要为 BillingContact 添加别名以允许您访问它的地址.

I believe you might need to add an alias to BillingContact to allow you access to it's Address.

类似于:

var criteria = DetachedCriteria.For<Order>()
  .CreateAlias("BillingContact", "bc")
  .SetFetchMode("BillingContact", FetchMode.Eager)
  .SetFetchMode("bc.Address", FetchMode.Eager)

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