获取子嵌套集合实体的元素联合 [英] Get Element Union of Child Nested Collection Entities

问题描述

大家好！

这是我无法弄清楚(也无法通过Google搜索)的内容

鉴于以下实体:

Good day everyone!

Here''s something I''m not able to figure out (and not able to google out)

Given the following Entities:

class EntityA {
   public int Aid {get;set}
   public ICollection<entitya> AEntities {get;set;}
   public ICollection<entityb> BEntities {get;set;}
}

class EntityB {
   public int BId {get;set;}
   public int AId {get;set;} //ForeingKey
}</entityb></entitya>

所以，我有一个EntityA，它具有:
-子级" EntityA的列表(通常是多对多关系，其中A可以指B，反之亦然)
-EntityB的列表

有没有办法像这样:

So, I have an EntityA which has:
- a list of "children" EntityA (techincally it''s a many to many relationship, in which A can refer to B and vice versa)
- a list of EntityB

is there a way to have something like:

//get my "main" entity
EntityA myEntityA = db.EntityA.Single(m => m.Id = myId); 

//get all EntityB items which are children of all of my "related" myEntityA.AEntities
ICollection<entityb> myEntitiesB = myEntityA.AEntities.All.BEntities;</entityb>

最后，myEntitiesB应该包含与我的主要实体相关的任何EntitiesA的所有EntityB子级，但是上面的代码无法编译.也许这只是命令sintax中的一小部分，但是我无法通过google找到解决方案(我发现很难对我需要的内容进行精确"搜索，并且发现了数十个结果页面与我的问题无关)

我可以使用以下方法:

At the end, myEntitiesB should contais all the EntityB children of any of the EntitiesA related to my main entity, but the code above doesn''t compile. Maybe it''s just a little thing in the command sintax, but I''m not able to find a solution with google (I find difficult to do a "precise" search for what I need, and I found dozens of result pages wich don''t relate to my question)

I could use following approach:

int[] MyChilderEntityAIds = {1;2;....;n}; //get the Ids of my EntityA "children"

var q =
   from x in db.EntitiesB
   where MyChilderEntitiAIds.Contains(x.AId)
   select x;

但是我想知道这是否是唯一"方式(编程很少只有一种方式来完成某件事)，或者我是否可以采用类似于第一个示例的方式来做到这一点.

如果问题中有不清楚的地方，请通知我.

预先感谢您，

Alberto

but I would like to know if this is the "only" way (programming rarely has only one way to accomplish something) or if I can do it in a way similar to the first example.

If something in the question is not clear, please let me know.

Thank you in advance,

Alberto

推荐答案

这是我为任何人找到的内容:

Here what I found for anyone:

IEnumerable<EntityB> allEntitiesB = myEntityA.AEntities.SelectMany(m => m.BEntitites);

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