同一类之间的实体框架关系 [英] Entity Framework relation between the same classes

问题描述

我有一个 Location 类，并且我希望该类具有对另外两个 Location 对象的引用:PreviousLocation和NextLocation.我已经尝试过了:

 公共类位置{public int LocationId {get;放;}[ForeignKey("LocationId")]public Location PreviousLocation {get;放;}[ForeignKey("LocationId")]public Location NextLocation {获取；放;}} 

但是在运行 Add-Migration 命令时给了我一个错误:实体类型'Location'中有多个导航指向相同的属性集-使用ForeignKeyAttribute的'LocationId'.

有人可以给我看一个如何实现我想要的行为的例子吗?

解决方案

尝试一下.这将允许递归或分层引用.

 公共类位置{public int LocationId {get;放;}public int NextLocationId {get;放;}public int PreviousLocationId {get;放;}[ForeignKey("PreviousLocationId")]public Location PreviousLocation {get;放;}[ForeignKey("NextLocationId")]public Location NextLocation {获取；放;}} 

I have a Location class, and I want that class to have references to another two Location objects: PreviousLocation and NextLocation. I have tried this:

public class Location
{
    public int LocationId { get; set; }

    [ForeignKey("LocationId")]
    public Location PreviousLocation { get; set; }
    [ForeignKey("LocationId")]
    public Location NextLocation { get; set; }
}

But it gave me an error when running Add-Migration command: There are multiple navigations in entity type 'Location' which are pointing to same set of properties - 'LocationId' using ForeignKeyAttribute.

Could anybody show me an example of how to achieve my desired behavior?

解决方案

Try this. This will allow Recursive or hierarchical referencing.

public class Location
{
    public int LocationId { get; set; }

    public int NextLocationId { get; set; }
    public int PreviousLocationId { get; set; }

    [ForeignKey("PreviousLocationId")]
    public Location PreviousLocation { get; set; }
    [ForeignKey("NextLocationId")]
    public Location NextLocation { get; set; }
}

这篇关于同一类之间的实体框架关系的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！