代码中的多对多关系第一个模型 - ASP.NET mvc5 [英] Many to many relationship in code first model - ASP.NET mvc5
问题描述
大家好！我正在处理代码优先数据库，我在Model文件夹中创建了自己的模型，我不使用实体。我有一个名为Event的模型类，由以下字段组成：EVENTID（STRING）DATE DESCRIPTION IMAGE。我现在要做的是，创建另一个名为Home的类，其中包含类似HOMEID（STRING）DESCRIPTION LINK的列，并且此表类Home必须与类Event有多对多的关系.i从此链接阅读本教程https ：//www.infragistics.com/community/blogs/b/dhananjay_kumar/posts/how-to-create-relationships-between-entities-in-the-entity-framework-code-first-approach，但有些事情并不清楚。在自己的列中，我希望将EventID作为导航字段添加为Home类中的外键，以便它将导航到Event类的字段ID。让我假装我已经在两个表的数据库中插入了一行：
Hi all!im working on code first database , i created my own model in Model folder and im not working with entities . I have a model class that is named Event and consists of the fields :EVENTID(STRING) DATE DESCRIPTION IMAGE . What am i trying to do now is , to create another class named Home with columns like HOMEID(STRING) DESCRIPTION LINK , and this table class Home must have a many to many relationship with the class Event .i read this tutorial from this link https://www.infragistics.com/community/blogs/b/dhananjay_kumar/posts/how-to-create-relationships-between-entities-in-the-entity-framework-code-first-approach , but something isnt clear . Insted of its own columns , i want to add EventID as navigation field ,as foreign key in Home class , so that it will navigate to field ID of Event class. Lets pretend i have a row inserted already in database in two of the tables :
Event:
EVENTID:TEST
DATE:01-01-2001
DESCRIPTION:TEST
IMAGE:TEST
_______Home:_________________
HOMEID:TEST1
DESCRIPTION:TEST1
LINK:TEST1
现在，当我使用创建视图添加Home对象时，能够做某事像这样：
So now , when i use create view to add a Home object , be able to do something like this :
Create Home View fields:
HOMEID : test2
DESCRIPTION:test2
LINK : test2
EVENTID :(HERE WE TYPE THE ID OF EVENT OBJECT THAT EXIST IN DATABASE ALREADY) TEST
然后我渲染这个创建的Home对象的详细信息视图，其id为'test2'，能够看到自己的字段和事件表相关字段：
DETAILS VIEW：
Then when i render the Details view of this created Home object with id 'test2' , be able to see something its own fields and Event table related fields :
DETAILS VIEW :
HOMEID : test2
DESCRIPTION:test2
LINK : test2
EVENTID:TEST
DATE:01-01-2001
DESCRIPTION:TEST
IMAGE:TEST
i APPRICIATE每次帮助。提前很多。
我的尝试：
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i APPRICIATE EVERY HELP.THANKS A LOT IN ADVANCE.
What I have tried:
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推荐答案
创建多对多连接的标准方法是创建所谓的结表。
根据您在上面提供的内容（表：事件&表：主页）您将创建第三个表 - 通常名为 Event__Home ，其中包含以下列;
a）主键
b）外键到事件表
c）Home表的外键
当你在Event&添加新的引用时主页在Event__Home表中创建一个新记录，其中包含Event Id&家庭ID。
活动模型&然后应该更新Home以包含来自Event__Home表的集合。
MVC将允许您遍历这些以显示相关表中的其他值。
以下文章将为您提供有关多对多连接等的其他信息;
MSDN：操作方法：多对多关系 [ ^ ]
亲切的问候
The standard method of creating a many-to-many join is to create what is known as a junction table.
Based on what you have provided above (Table: Event & Table: Home) you would create a third table - normally named Event__Home that consists of the following columns;
a) Primary Key
b) Foreign Key to Event table
c) Foreign Key to the Home table
When you add a new reference between Event & Home a new record is created in the Event__Home table that comprises of the Event Id & the Home Id.
The Models for Event & Home should be then updated to include collections from the Event__Home table.
MVC will allow you to traverse these to display additional values from the relevant table.
The below article will give you additional information on Many-to-Many joins etc;
MSDN: How-To: Many to Many Relationships[^]
Kind Regards
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