Fluent nhibernate Fluent NHibernate关系映射和保存异常

我是NHibernate的新手，正在尝试使用Fluent的自动映射功能，这样我就不需要手动维护单独的XML文件。不幸的是，我遇到了引用实体的问题，特别是“Fluent\u NHibernate\u Demo.Domain.Name.Id的getter出现异常”-System.Reflection.TargetException:对象与目标类型不匹配

虽然映射类生成了正确的SQL（即，创建的表具有正确的索引），但我至少在其中一个映射类中出现了错误

my domain模型和映射的实现包括：

---

Name.cs

public class Name
{
    public virtual int Id { get; protected set; }
    public virtual string First { get; set; }
    public virtual string Middle { get; set; }
    public virtual string Last { get; set; }
}

public class Person
{
    public virtual int Id { get; protected set; }
    public virtual Name Name { get; set; }
    public virtual short Age { get; set; }
}

public NameMap()
{
    Table("`Name`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    Map(x => x.First).Column("`First`").Not.Nullable().Length(20);
    Map(x => x.Middle).Column("`Middle`").Nullable().Length(20);
    Map(x => x.Last).Column("`Last`").Not.Nullable().Length(20);
}

public PersonMap()
{
    Table("`Person`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    References<Name>(x => x.Name.Id, "`NameId`").Not.Nullable();
    // There's no exception if the following line is used instead of References
    // although no constraint is created
    // Map(x => x.Name.Id).Column("`NameId`").Not.Nullable();
    Map(x => x.Age).Column("`Age`").Nullable();
}

---

Person.cs

public class Name
{
    public virtual int Id { get; protected set; }
    public virtual string First { get; set; }
    public virtual string Middle { get; set; }
    public virtual string Last { get; set; }
}

public class Person
{
    public virtual int Id { get; protected set; }
    public virtual Name Name { get; set; }
    public virtual short Age { get; set; }
}

public NameMap()
{
    Table("`Name`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    Map(x => x.First).Column("`First`").Not.Nullable().Length(20);
    Map(x => x.Middle).Column("`Middle`").Nullable().Length(20);
    Map(x => x.Last).Column("`Last`").Not.Nullable().Length(20);
}

public PersonMap()
{
    Table("`Person`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    References<Name>(x => x.Name.Id, "`NameId`").Not.Nullable();
    // There's no exception if the following line is used instead of References
    // although no constraint is created
    // Map(x => x.Name.Id).Column("`NameId`").Not.Nullable();
    Map(x => x.Age).Column("`Age`").Nullable();
}

---

NameMap.cs

public class Name
{
    public virtual int Id { get; protected set; }
    public virtual string First { get; set; }
    public virtual string Middle { get; set; }
    public virtual string Last { get; set; }
}

public class Person
{
    public virtual int Id { get; protected set; }
    public virtual Name Name { get; set; }
    public virtual short Age { get; set; }
}

public NameMap()
{
    Table("`Name`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    Map(x => x.First).Column("`First`").Not.Nullable().Length(20);
    Map(x => x.Middle).Column("`Middle`").Nullable().Length(20);
    Map(x => x.Last).Column("`Last`").Not.Nullable().Length(20);
}

public PersonMap()
{
    Table("`Person`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    References<Name>(x => x.Name.Id, "`NameId`").Not.Nullable();
    // There's no exception if the following line is used instead of References
    // although no constraint is created
    // Map(x => x.Name.Id).Column("`NameId`").Not.Nullable();
    Map(x => x.Age).Column("`Age`").Nullable();
}

---

PersonMap.cs

public class Name
{
    public virtual int Id { get; protected set; }
    public virtual string First { get; set; }
    public virtual string Middle { get; set; }
    public virtual string Last { get; set; }
}

public class Person
{
    public virtual int Id { get; protected set; }
    public virtual Name Name { get; set; }
    public virtual short Age { get; set; }
}

public NameMap()
{
    Table("`Name`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    Map(x => x.First).Column("`First`").Not.Nullable().Length(20);
    Map(x => x.Middle).Column("`Middle`").Nullable().Length(20);
    Map(x => x.Last).Column("`Last`").Not.Nullable().Length(20);
}

public PersonMap()
{
    Table("`Person`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    References<Name>(x => x.Name.Id, "`NameId`").Not.Nullable();
    // There's no exception if the following line is used instead of References
    // although no constraint is created
    // Map(x => x.Name.Id).Column("`NameId`").Not.Nullable();
    Map(x => x.Age).Column("`Age`").Nullable();
}

---

---

如前所述，创建的模式是正确的，但我无法使用上述代码保存。使用Fluent NHibernate创建外键约束的正确方法是什么？

如果您想通过ID引用名称，那么这就是您应该做的。NHibernate足够聪明，能够弄清楚Person上的实际FK字段应该是什么以及它应该指向哪里；也就是说，毕竟ORM是设计用来执行的任务

尝试以下映射：

public PersonMap()
{
    Table("`Person`");
    Id(x => x.Id).Column("`Id`").GeneratedBy.Identity();
    References(x => x.Name, "`NameId`").Not.Nullable();        
    Map(x => x.Age).Column("`Age`").Nullable();
}

您已经映射了人员和名称；因此，NHibernate知道哪个属性是Name的ID属性，并且可以在Person上创建和遍历外键