流利的NHibernate HasManyToMany()映射

本文介绍了流利的NHibernate HasManyToMany()映射的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

在使用多对多关系的Fluent NHibernate示例中，我遇到了问题.我试图找出类似案例的例子，但发现了很多吨，但我仍然遇到同样的问题.

I am having a problem in Fluent NHibernate example utilizing the Many-to-Many relationships. I tried to find out examples on a similar case, and I found tons, but I'm still having the same problem.

运行测试项目时，会引发以下异常:

When running the test project, the following exception is thrown:

NHibernate.PropertyAccessException:项目.Entities.User.UserName的吸气剂发生异常---> System.Reflection.TargetException:对象不匹配目标类型.

NHibernate.PropertyAccessException: Exception occurred getter of project.Entities.User.UserName ---> System.Reflection.TargetException: Object does notmatch target type.

这是表格的图像:

和代码

 public UsersMap()
    {

        this.Table("Users");
        Id(x => x.UserName).Column("Username").GeneratedBy.Assigned();

        Map(x => x.FirstName);
        Map(x => x.LastName);
        Map(x => x.Password);
        Map(x =>x.EMail);
        Map(x => x.Title);
        Map(x => x.Division);


        HasManyToMany<User>(x => x.Roles)
            .Table("UserInRoles").ParentKeyColumn("Username")
            .ChildKeyColumn("Usernamepk")
           .Cascade.SaveUpdate().LazyLoad();


    }

  public RolesMap()
    {
        this.Table("Roles");
        Id(x => x.ID).GeneratedBy.Assigned().Column("ID");
        Map(x => x.RoleName).Length(50);

        HasManyToMany<User>(x => x.Users)
            .Table("UserInRoles").ParentKeyColumn("ID")
            .ChildKeyColumn("RoleIdpk").Cascade.SaveUpdate().LazyLoad();

    }

这是代码，网络上的大多数示例和Fluent Nhibernate映射页面都是以相同的方式编写的，所以有什么想法吗?

here is the code, most examples on the web and the Fluent Nhibernate mappings page are written in the same way, so any ideas ?

推荐答案

关于我在项目中使用的代码，我将以这种方式定义您的manyTomany关系:

Regarding to code I am using in my project I would define your manyTomany relations this way:

 public UsersMap()
    {
...
            HasManyToMany(x => x.Roles)
                .WithTableName("UserInRoles")
                .WithParentKeyColumn("Usernamepk")
                .WithChildKeyColumn("RoleIdpk");
    }

  public RolesMap()
    {
...
            HasManyToMany(x => x.Users)
                .WithTableName("UserInRoles")
                .WithParentKeyColumn("RoleIdpk")
                .WithChildKeyColumn("Usernamepk");

    }

这样的定义对我有用.首先选中此选项，然后使用LazyLoading和其他一些属性进行装饰.

Such a definitions works for me.Check this first then decorate with LazyLoading and some other properties.

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