使用NHibernate从外键获取MySQL表中的数据

Question

我有一个带有树表的mysql数据库：Author，PublishingHouse和Book。最后一个有两个外键 - AuthorId和PublishingId。我为每个表和NHibernate的映射文件创建了类。下一步是从Book表中获取数据并将其传递给我的MVC项目视图。我不能这样做，因为在我的BookController中我得到了这样的例外：NHibernate.PropertyAccessException: Invalid Cast (check your mapping for property type mismatches);

那是我现在的代码：

楷模

public class Author
{
    public virtual int Id { get; set; }
    public virtual string FirstName { get; set; }
    public virtual string LastName { get; set; }
}

public class PublishingHouse
    {
        public virtual int Id { get; set; }
        public virtual string Name { get; set; }
        public virtual string City { get; set; }

    }

public class Book
    {
        public virtual int Id { get; set; }
        public virtual string UDK { get; set; }
        public virtual string BBK { get; set; }

        public virtual string AuthorsSign { get; set; }
        public virtual string ISBNrus { get; set; }
        public virtual string ISBNeng { get; set; }

        public virtual Author Author { get; set; }
        public virtual string Name { get; set; }
        public virtual PublishingHouse PublishingHouse { get; set; }

        public virtual int Year { get; set; }
        public virtual int Pages { get; set; }
        public virtual int Circulation { get; set; }

        public virtual bool IsRead { get; set; }
        public virtual int Rating { get; set; }
        public virtual string Annotation { get; set; }
    }

NHibernate映射

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true" assembly="InFolio_HomeLib" namespace="InFolio_HomeLib.Models">
  <class name="Author" table="Author" dynamic-update="true" >
    <cache usage="read-write"/>
    <id name="Id" column="Id" type="int">
      <generator class="native" />
    </id>
    <property name="FirstName" />
    <property name="LastName" />
  </class>

  <class name="PublishingHouse" table="PublishingHouse" dynamic-update="true" >
    <cache usage="read-write"/>
    <id name="Id" column="Id" type="int">
      <generator class="native" />
    </id>
    <property name="Name" />
    <property name="City" />
  </class>

    <class name="Book" table="Book" dynamic-update="true" >
    <cache usage="read-write"/>
    <id name="Id" column="Id" type="int">
      <generator class="native" />
    </id>
    <property name="UDK" />
    <property name="BBK" />
    <property name="AuthorsSign" />
    <property name="ISBNrus" />
    <property name="ISBNeng" />   

    <set name="Author" table="Author">
      <key column ="Id" />
      <one-to-many class="Author"/>
    </set>    

    <property name="Name" /> 

    <set name="PublishingHouse" table="PublishingHouse">
      <key column ="Id" />
      <one-to-many class="PublishingHouse"/>
    </set>    

    <property name="Year" />
    <property name="Pages" />
    <property name="Circulation" />
    <property name="IsRead" />
    <property name="Rating" />
    <property name="Annotation" />
  </class>
</hibernate-mapping>

BookController我得到一个例外：

    public ActionResult Index()
    {
        using (ISession connectionDB = NHibertnateSession.OpenSession())
        {
            var books = connectionDB.Query<Book>().ToList();
            return View(books);
        }
    }

我可以轻松地从Author和Publishing表中获取数据，它们非常简单，但Book表对我来说并不那么明显。我在绘图时错了吗？或者别的地方？

使用NHibernate从外键获取MySQL表中的数据

5.1.11. many-to-one