MVC / EF Code First ICollection Objects - asp.net-mvc

Question

I am using MVC5 Code First and have a couple of classes that look like;
public class Asset
{
public int Id { get; set; }
public string FileName { get; set; }
public virtual ICollection<Category> Categories { get; set; }
}
public class Category
{
public int CategoryId { get; set; }
public int AssetId { get; set; }
public string CategoryName { get; set; }
public string Description { get; set; }
}
I would like to return a view that lists all Assets that have a particular Category. I was hoping for something along the lines of
public ActionResult ListByCategory(string categoryName)
{
var model =
from r in _db.Assets
.Where(r => r.Categories.CategoryName == categoryName)
select r;
return View(model);
}
I know I have some assets from my seed method that have categories that exist. But the compiler is saying "System.Collection.Generic.ICollection Does not contain a definition for CategoryName and no extension method could be found, am I missing a reference?" This is on my .Where line.
I don't fully understand what it's trying to tell me. I do have a reference to my Models as I can reference them elsewhere within the controller. I know that a single Asset might be in several Categories, hence I created the ICollection at the class level.
Here is my context class;
public class AssetsDb : DbContext
{
public AssetsDb() : base("DefaultConnection")
{
}
public DbSet<Asset> Assets { get; set; }
public DbSet<Category> Categories { get; set; }
}
Could somebody help my understanding on how I can get to my underlying data? I'm trying to learn EF / MVC so appreciate any help.
Thanks.

Answer 1

You cannot get a CategoryName from a collection of categories, you need to check the name of each category within the collection.
Try using this query instead:
var model =
from r in _db.Assets
.Where(r => r.Categories.Any(c => c.CategoryName == categoryName))
select r;