在nhibernate 4.0双向关系

问题描述

我有一个在NHibernate 3.1上工作完美的代码，但是当它不能在NHibernate 4.0上运行时，所以这是类关系。

  public class Employee：BaseEntity 
 {
 ... 
 Public Department Dept {get;组; } 
} 
 
 public class Department：BaseEntity 
 {
 ... 
 public IList< Employee>员工{get;组; } 
} 
  

对于映射我们有这个

  DepartmentMap：ClassMap< Department> 
 {
表（....）; 
 HasMany（x => x.Employees）.KeyColumn（DeptId）。Not.KeyNullable（）; 
} 
 
 
 EmployeeMap：ClassMap< Employee> 
 {
引用（x => x.Dept）.Column（DeptId）; 
} 
  

当我添加这样的员工时

  var dept = session.Load< Department>（deptId）; 
 newEmployee.Dept = dept; 
 session.Save（newEmployee）; 
  

但是却出现错误：

阅读我必须以两种方式添加关系，所以我将其修改为

  var dept = session.Load< Department> ;（DEPTID）; 
 newEmployee.Dept = dept; 
 dept.Employees.Add（newEmployee）; 
 session.Save（newEmployee）; 
  

但现在我有这个错误：

所以，我想知道如何解决这个问题，以及在哪里可以阅读有关双向的NHibernate的变化

我找到了这个问题的解决方法：
解决这个问题的方法是在父文件的映射中添加Inverse。
因此，Department的映射是：

  DepartmentMap：ClassMap< Department> 
 {
表（....）; 
 HasMany（x => x.Employees）.KeyColumn（DeptId）。Inverse（）。Not.KeyNullable（）; 
} 
  

I have a code that was working perfectly on NHibernate 3.1, but when it is not working on NHibernate 4.0

So, this is the class relations

public class Employee : BaseEntity
{
    ...
    public Department Dept { get; set; }
}

public class Department : BaseEntity
{
    ...
    public IList<Employee> Employees { get; set; }
}

and for the mapping we have this

DepartmentMap : ClassMap<Department>
{
     Table("....");
     HasMany(x => x.Employees).KeyColumn("DeptId").Not.KeyNullable();
}


EmployeeMap : ClassMap<Employee>
{
     Reference(x => x.Dept).Column("DeptId");
}

and when I am adding an employee like that

var dept = session.Load<Department>(deptId);
newEmployee.Dept = dept;
session.Save(newEmployee);

But it is throwing an error:

I read that I have to add the relation in two ways, so I modified it to this

var dept = session.Load<Department>(deptId);
newEmployee.Dept = dept;
dept.Employees.Add(newEmployee);
session.Save(newEmployee);

But now I have this error :

So, I want to know how to fix it and where I can read about the changes in NHibernate about this with bi-direction

解决方案

I found the fix for the problem:The fix for the problem is to add Inverse to the mapping of the parent file.So, the mapping for Department will be:

DepartmentMap : ClassMap<Department>
{
     Table("....");
     HasMany(x => x.Employees).KeyColumn("DeptId").Inverse().Not.KeyNullable();
}

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