CODEWITHSUNDEEP
c#linqentity-framework
ollo
ollo

Reputation: 99

linq to entities cannot convert type Icollection to type List

I'm using Entity Framework. I have the following entities:

public class Articolo
{
    ..
    public virtual ICollection<Fornitore> Fornitori { get; set; }
}

public class Fornitore
{
  ...
   public virtual ICollection<Articoli> Articoli { get; set; }    }

the following code:

List<Fornitore> result = new List<Fornitore>();
var r = zefiroContext.Articoli.Where(p => p.Id == IdArticolo).Select(p => p.Fornitori).ToList();
result = r;

gives a compiler error:

Cannot implicitly convert type 'System.Collections.Generic.List < System.Collections.Generic.ICollection < prova2.Model.Fornitore>>' to 'System.Collections.Generic.List < prova2.Model.Fornitore>'

how can I get my List < Fornitore > ?

Upvotes: 1

Views: 2493

Answers (2)

Basic
Basic

Reputation: 26766

Each Articolo has Many Fornitori - So you're getting a list of lists...

You may be meaning to get only the matching single item with a matchign id...

var r = zefiroContext.Articoli.First(p => p.Id == IdArticolo).Select(p => p.Fornitori).ToList();

Upvotes: 0

Quintin Robinson
Quintin Robinson

Reputation: 82375

Well you are actually trying to select multiple collections and I think that is where your problem is, changing your Select to SelectMany may resolve the issue for you but I am not sure if that is your intended functionality. What is going to happen is the SelectMany is going to condense all the individual result sets into a single collection which then can be turned into a list of the model type vs a list of collections of the model type.

var r = zefiroContext.Articoli.Where(p => p.Id == IdArticolo).SelectMany(p => p.Fornitori).ToList();

Upvotes: 4

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