级联删除基本“节点”实体 [英] Cascade Delete for basic "Nodes" Entity

问题描述

我似乎遇到了应该（我假设）的问题，非常简单。 我真的很感激任何帮助或指示。

I seem to be having problems with something that should (I assume), be very simple.  I would really appreciaate any help or pointers.

我有一个非常基本的"节点"。实体：

I have a very basic "Node" Entity:

NodeId - Int32，key

NodeId - Int32, key

NodeName - String

NodeName - String

ParentNode - 节点（0 .. 1）

ParentNode - Node (0..1)

子节点 - 节点集合（0 .. *）

SubNodes - Collection of Node (0..*)

我想删除父节点以自动删除所有子节点。  这可能吗？

I would like the deletion of a parent node to automatically delete all subnodes.  Is this possible?

当我将End2OnDelete规则设置为级联时，我会收到：

When I set the End2OnDelete rule to cascade I receive:

错误    1   错误132：关系'NodeModel.NodeNode'上的结束'Node1'不能指定操作，因为它的多重性是'*'。无法在具有多重性'*'的结尾处指定操作。    C：\MemoryScienceDevelopment\TreeDeleteTest1\TreeDeleteTest1\NodeModel.edmx   
21    5    TreeDeleteTest1

Error    1    Error 132: End 'Node1' on relationship 'NodeModel.NodeNode' cannot have operation specified since its multiplicity is '*'. Operations cannot be specified on ends with multiplicity '*'.    C:\MemoryScienceDevelopment\TreeDeleteTest1\TreeDeleteTest1\NodeModel.edmx    21    5    TreeDeleteTest1

我应该以不同方式构建我的节点实体吗？ 我应该以不同方式设置OnDelete规则吗？ 我真的不必为级联删除编写我自己的递归例程吗？是吗？

Should I structure my Node Entity differently?  Should I set up the OnDelete rules differently?  I don't really have to write my own recursive routines for cascade deletes, do I?

 

任何帮助都将不胜感激。

Any help would be greatly appreciated.

谢谢，

Chris

推荐答案

EF仅创建数据库中存在级联删除的元数据。

如果您没有在数据库中配置级联删除，则不会发生级联删除。

我建议您阅读Alex James关于此主题的帖子：
http ：//blogs.msdn.com/b/alexj/archive/2009/08/19/tip-33-how-cascade-delete-really-works-in-ef.aspx



我希望它能帮到你。

Hi,

EF only creates metadata that a cascade delete exists in the database.
If you didn't configure the cascading delete in the database no cascading delete will happen.
I encourage you to read Alex James's post about this subject here: http://blogs.msdn.com/b/alexj/archive/2009/08/19/tip-33-how-cascade-delete-really-works-in-ef.aspx

I hope it will help you.

这篇关于级联删除基本“节点”实体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！