C＃LINQ to Entities查询两个不同属性的交集 [英] C# LINQ to Entities query for the intersection of two different properties

问题描述

铅笔具有Pencil.Id（int）和Pencil.Colors （IEnumerable）属性

Pen 具有Pen.Id（int）和Pen.Colors（IEnumerable）属性

颜色具有Id和名称。

铅笔与颜色有关系多对多）
笔与颜色（多对多）有关系

我想构建一个查询，这将显示给我一样我拿着笔的彩色铅笔。

我正在使用以下LINQ到实体查询：

  int id = id_of_the_pen_that_i_am_holding; 
笔p = db.Pens.Find（id）; 
 var list = from m in db.Pencils其中m.Colors.Intersect（p.Colors）！= null select m; 
  

颜色模型是IEnumerable，所以它有1种以上的颜色。例如;笔有15种不同的颜色，铅笔有25种不同的颜色。我想带上对应的铅笔，如果我拿着的笔的一种颜色也可以在那支铅笔的调色板中使用。

但是我正在使用常量变量（例如int或string而不是对象）的例外。

我该怎么办？感谢您的帮助。

EDITED：
我为下一个可能的问题创建了一个新问题： C＃LINQ to Entities - 对象和收集对象

解决方案

  int id = id_of_the_pen_that_i_am_holding; 
笔p = db.Pens.Find（id）; 
 var penColorIds = p.Color.Select（m => m.Id）.ToList（）; 
 var list = db.Pencils.Where（pencil => pencil.Color.Any（color => penColorIds.Contains（color.Id））; 
  pre> 
I have 3 models named:

  
Pencil having Pencil.Id(int) and Pencil.Colors(IEnumerable) Property
  
  
Pen having Pen.Id(int) and Pen.Colors(IEnumerable) Property
  
  
Colors having Id and name.
Pencil has a relation with colors (many-to-many)
Pen has a relation with colors (many-to-many)

I want to build a query which will show me the same colored pencils for the pen that I am holding. 

I am using the below LINQ-to-Entities query:
int id = id_of_the_pen_that_i_am_holding;
Pen p = db.Pens.Find(id);
var list = from m in db.Pencils where m.Colors.Intersect(p.Colors) != null select m;
Colors model is IEnumerable so it has more than 1 color. For example; the pen has 15 different colors and pencil is having 25 different colors. I want to bring the corresonding pencil if one of the colors of the pen that I am holding is also avaialable in the color palette of that pencil.

But I am getting an exception to use regular variables like int or string rather than objects.

What can I do? Thanks in advance for your helps.

EDITED:
I've created a new question for a next possible issue: C# LINQ to Entities- Properties on the intersection of an object and a collection of objects
解决方案
int id = id_of_the_pen_that_i_am_holding;
Pen p = db.Pens.Find(id);
var penColorIds = p.Color.Select(m => m.Id).ToList();
var list = db.Pencils.Where(pencil => pencil.Color.Any(color => penColorIds.Contains(color.Id));


                        
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